I'll open by first asking a question, how many do actually buy characteristic advances past step 2 (Intermediate)? Espicially if your group is small (3-4 players).

My purposal is this:

1. Characteristic advances cost the total listed for its level.(For an Arbitrator, Intermediate Weapon Skill costs a total of 500 XP instead of 750XP)

2. You can only rise a Characteristic once every two ranks, Meaning you have to be at least rank 3 in order to have +10 to a Characteristic.

3. Pre Acsention you are Limited Getting +115 Points/23 Characteristic Advances

4. Post Ascension you can get a further +55 points/11 Characteristic Advances.

Is this to generous? My instinct says no, this way my players can eventually get about 40%-45% Success rate on their Trained skills for a Challenging test, and better for skills that they have invested more heavily into. Their basic skills become more of an an asset.

I would still ask my players to develop a theme for their characters instead of sweeping up a bunch of trained skills.

I made for myself using this method an Arbitrator who has the following Advances: (Note this character is built from the bottom up)

Home World: Schola Progenum. (A Schola In Hive Sibellus on Scintilla)

Base #Advances Cost(XP) Final Profile

WS 36 *2 500 46

BS 31 *2 250 41

S 34 34

T 45 *3 500 60

Ag 35 *1 500 40 4250 (This is the amount of XP Spent on characteristics using my system)

I 33 *3 500 48

P 32 *2 500 42

W 40 *4 1000 60 (+10 For The Transition Package into Inquisitor)

F 32 *2 500 42

Sound Constitution *6 800 5050(XP Spent afther buying extra Wounds)

Background:
Calixian Pattern Killings: 200 5250(XP Spent after buying background package)

+5 Perception

Talents:

Talented Inquiery

REDUNDANT TALENT:

Melee W:Primitive-> Pistol SP (My group allows the trade of redundant talents, subject to GM apporoval)

LATENT PSYKER:

Psy Rating 1 + Invocation(300) 700 5850 (XP spent after buying up this trait)

Psy Rating 2+3(400)

this is how my group handles latent psykers, you can't get PSY 1 before rank 3)

SKILLS:

Awareness(100) Ciphers:Underworld(100) 6050

Command +20(300) Common L:Arbites+10(100) 6450

Common L:Underworld,Imperium, Adminastratum(150)#1 6600

Dodge+10(200) Drive.Ground,(100) 6900

Forbidden L.Cults (200) Forbidden L. Mutants(200) 7300

Inquiry+20(200) Interogation+10(200) Intimidate(100) 7800

Logic(200) Scholastic L:Judgement+Tactica(200) 8200

Scruteny(100) Search+10(200) Shadowing(200) 8700

Silent Move(200) Tracking(100) Tech-Use(200) 9200

Charm(100) Concealment(100) Swim(100) 9500

Climb(100) Decive(100) Securety(100) 9800

TALENTS:

Air of Authority(200) Ambidexterous(100) Armour of Contempt(200) Arms Master(100) 10400

Combat Master (200) True Grit(100) 10700

Die Hard(100) Iron Jaw(100) Iron Discipline(100) 11000

Into the Jaws of Hell(100) Hardy(100) 11200

Melee WT:Chain(200) Pistol:Bolt,Las,SP(100) Basic Weapon: Las/SP (0) 11500

Quiock Draw(0) Swift Attack (300) 11800

Two WW.Ballistic,Melee (400) Wall of Steel(200) 12400

Ligth Sleeper (100) Master Orator(200) Step Aside(100) 12800

Talented;Command(100) Hip Shooting(100) 13000

As can see this caracter is quite versatile but is focused on Investigations and Command. He's also skilled in personal combat, at least defensive combat. He's diverse enoough that a a small acolyte cell can be involved in most kind of adventures

In the pre-Ascension game I play in the Assassin in our group has maxed out his Agility. I plan on maxing my Adepts Intelligence and Willpower, bought 1 and 2 advances respectively so far, after that everything else gets worked on. Our Guardsman has purchased 3 WS, 3 Strength and 4 Toughness advances if I recall correctly. Our Scum was near maxed on BS and Agility. I think Loki's psyker has purchased either 3 or 4 of his Willpower advances, and has been working on WS, Strength and Agility as well. I'm not sure where LeBlanc and Kael are on advances

Honestly I believe the costs are fine, as characteristic advances at their most expensive tend to be more cost effective then buying mastery for multiple skills based off of the characteristic. Even with your +20 running anywhere from 1,350xp to as much as 4,750xp. After all, how many advanced skills are there based on Int? Even a Guardsman has an impressive number of Intelligence based skills; Common Lores, Demolitions, Medicae, Secret Tongues, Ciphers, etc.

But, if you feel a change is in order for a game you're running, so be it. It's your game.

-=Brother Praetus=-

I know in our group (mind you, we have some 6-7 players) my Assassin has maxed Agility and is working on his weapon and Ballistic and Toughness, our Adept is near max on Int, we have our Cleric at max fellowship I think, and our Psyker is working on maxing out Willpower.

Also, I think our Tech Priest of Awesome is maxed on toughness and Int.

I know our Tech-Priest bought every available Fellowship advance as soon as he could. Oh, wait...

I've run one game where I divorced the Characteristic Advances from the Professions. Every character, regardless of Profession, selects three Characteristics to be Favored. Favored Characteristics advance for Free/250/500/750 while other Characteristics advance for 250/500/750/1,000. This does mean that every character gets three free +5 advances at character creation.

By divorcing the Characteristics from Profession, you get new opportunities like an Assassin with an aptitude for Fellowship instead of Ballistic Skill (a gladiator/duelist type), or for even more of a change, try a Scum with an aptitude for Weapon Skill, Strength and Toughness over Ballistic Skill, Agility, and Fellowship (a brutish thug). Sure, some characters might seem cross-type, such as an Adept without Intelligence as a Favored Characteristic, but not everyone is really in the Profession that best serves their natural aptitudes,so it works for us.

I went for straightforward cost simplification in my campaign: all characteristics advances cost the lowest rate (100/250/500/750) regardless of career.

I've never been overly keen on rigidly defined careers/classes/professions. Favouring a handful of characteristics for each Career effectively forces the players to take there characters in a more or less stereotypical direction, thus enforcing tightly specialised roles within the party. I prefer to use the Career as a starting point, and let campaign and character development show what is best for a given character concept. For instance, I see no reason to make it prohibitively expensive for a Guardsman to develop keen social skills (i.e. Fel). As I see it, the rules should assist in character generation and development, not define it.

My group and I have been perfectly happy with this system - greater diversity for character development while removing the need to consult tables to see how much any given advance costs. Besides, we don't really see eye to eye with the game designers on what would credibly be "the path of least resistance" for the careers in the book. And, since it's the Skills that let PCs tap into their characteristics properly, Career themes suffer nothing in terms of individuality.

Works for us, at least.