Please let me know if I got this right:

Let's say I want to buy a Common Quality Plasma Pistol (Ryza). According to page 118, this is a Very Rare item.

If I understand correctly, first I need to find this item. This is a Commerce (or Inquiry) Test. I go to a city with 200,000 population , so my Test suffers a penalty of -10 (Table 5-1) .

I spend One Week (Table 5-2 ) looking around, and then I roll my Commerce (or Inquiry) Test with a penalty of -10 . If I succeed, I've found the item (but I haven't acquired it yet).

Now I must roll an Acquisition Test, with a penalty of -20 because the item is Very Rare (Table 9-35) , but with a bonus of +30 because I only want to buy a single item (Table 9-35). Thus, roll under Profit Factor +10.

To Recap:

1) travel to a city with 100,000+ population,

2) spend a week looking,

3) roll Commerce (or Inquiry) Test at -10,

if you succeed,

4) roll Profit Factor Test at +10.

Right so far? I've another couple of questions about the same topic, but I'd like to know first if I got the basics.

Thanks in advance!

Your math seems to be correct.

Just want to point these as I have my book in front of me right now,

Table 5-2 ,

This table assumes that the Rogue Trader employs servants, negotiators, and factors who are practised in finding mercantile services and establishing compacts in haste.

A Rogue Trader and his retinue can either wait for their servants to complete the search and arrange purchase, or spend their own time to assist rather than undertaking other activities.

A successful Challenging (+0) Commerce Test (or another skill appropriate to the item or service sought at the discretion of the Game Master) made by an assisting player character can speed the search and ensuring negotiations.

A successful test reduces the time taken by one step, such as from months to weeks, or weeks to days.

Your math seems to be correct.

Just want to point these as I have my book in front of me right now,

Table 5-2 ,

This table assumes that the Rogue Trader employs servants, negotiators, and factors who are practised in finding mercantile services and establishing compacts in haste.

A Rogue Trader and his retinue can either wait for their servants to complete the search and arrange purchase, or spend their own time to assist rather than undertaking other activities.

A successful Challenging (+0) Commerce Test (or another skill appropriate to the item or service sought at the discretion of the Game Master) made by an assisting player character can speed the search and ensuring negotiations.

A successful test reduces the time taken by one step, such as from months to weeks, or weeks to days.

That would be one of my follow-up questions... :-)

If I'm letting my servants do the search, does it mean they roll the Commerce (or Inquiry) Test? What's their skill?

Are these servants members of my void-ship crew? Or is this something completely different?

Can they look for stuff while I'm travelling the Warp, or only when my ship is at some port?

Depends of the GM, if a RT wants to use -only- his crew, it would depend of the crew's general skill (Poor, Experienced, Expert, etc). But when I GMed, since the RT in question was docked in the planet and directing the efforts from afar (not being there) I used his Skill.

Yes, the servants of your Void-Ship, or one of your Void-Ships.

Yep, they can search for stuff while you're having your adventures. They can even carry Endeavours on their own, though smaller and more prone to failure.

Depends of the GM, if a RT wants to use -only- his crew, it would depend of the crew's general skill (Poor, Experienced, Expert, etc). But when I GMed, since the RT in question was docked in the planet and directing the efforts from afar (not being there) I used his Skill.

Yes, the servants of your Void-Ship, or one of your Void-Ships.

Yep, they can search for stuff while you're having your adventures. They can even carry Endeavours on their own, though smaller and more prone to failure.

Mh... seems looking for stuff personally is the best option, makes sense.

Another question: let's say I want to buy a plasma pistol (very rare) with a red-dot laser sight (scarce). Do I have to make TWO Commerce rolls to find both items separately, or just add a -5 penalty for each component, like the Acquisition Test?

Depends of the GM, if a RT wants to use -only- his crew, it would depend of the crew's general skill (Poor, Experienced, Expert, etc). But when I GMed, since the RT in question was docked in the planet and directing the efforts from afar (not being there) I used his Skill.

Yes, the servants of your Void-Ship, or one of your Void-Ships.

Yep, they can search for stuff while you're having your adventures. They can even carry Endeavours on their own, though smaller and more prone to failure.

Mh... seems looking for stuff personally is the best option, makes sense.

Another question: let's say I want to buy a plasma pistol (very rare) with a red-dot laser sight (scarce). Do I have to make TWO Commerce rolls to find both items separately, or just add a -5 penalty for each component, like the Acquisition Test?

As far as I know, yes. Though it could be easier to find them separately and have your friendly neighbourhood Explorator install it for you.