So my players wanted to find someone who could just about find them any gun they could wish regardless of legality after rolling a couple of triumphs I allowed them to find such a person (I think I uttered the fateful words "I have anything you would need"..... Whoops). After rolling a well again they were able to acquire them as a contact, so now they have access to someone who can get them just about any gun (I still get them to roll the check but there isn't anything beyond restriction aside from things that would be just about impossible to get itself). The two 'we like to kill things with big things' people understand the that there are weapons restrictions that very from place to place so there pretty good with what there allowed to bring around so I don't really have a problem with people wanting heavy reacting blasters if they want, just that they know you can't bring it on about 9/10 places.

I came up with the idea that to remain in such an exclusive clientele list for this dealer, is that the dealer would require there services from time to time to retrieve items if particular value or remove competitors or people that have failed to maintain there end of a deal. However I'd I didn't want that to be the only thing they would be doing to maintain ready access to them, so I have come fishing for ideas and solutions that any body can provide.

I'd think that the best way to staying on a preferred customer list would be to keep spending money buying stuff from the guy without doing anything to attract unwanted attention to his business. That's not necessarily as easy to do as it sounds.

have one of them take the black market contacts talent. this is exactly what this is for. in my group I went smuggler just so.we could.have it.

It depends on the personality and background of the contact.

Is he a gun-nut, a collector, a tinkerer, paranoid pirate, ...

with access thanks to his carreer in the Army/Navy, owning a legal shop, working for a crime syndicate,...

All that defines how and why he does his business.

So make that contact a person first.

Depending on that he might be stricter or more lenient when it comes to buying from your group and/or selling to them when they use those weapons to rake up huge bodycounts.

Getting chased by the I.I. or Navy for terrorism is not high on a professional traders wishlist, a pirate or outright Rebel is used to that but might object when civilians get caught in the crosshairs.

A good way to have good relations and remain a preferred buyer is to do things for the dealer. Have the dealer ask them for favours or to deal with certain issues exclusively, thus creating a rapport with this recurring npc. Essentially he becomes a source of adventures.

There is a Nicholas cage movie about an arms dealer. Perhaps it would give you inspiration. Also look for the criminal organization book from WEG star wars.

Also, he'd be pretty expensive. The more links in the chain from manufacturer to customer, the more expensive any given piece of equipment will be. Just look at how the Black Market Contacts talent works; assume the gun dealer has multiple ranks in that talent, but if he has to pay double the list price for a weapon you can be sure that he'll pass that expense on to his customers.

You could also have them gain some favor by acquiring items that the dealer desires. It could be rare collectible items, Correllian Whiskey, Trophies, and other such things for trade or even as gifts. It give the Dealer a reason to be amendable to the PC's. Might even loan or even gift the PC's an expensive weapon if favor is high enough instead of making them buy it.

Just an example from old DnD Campaign I was in. Our party was part of a large adventuring company that had a quarter master who could get us most of what we needed. Basically you could buy items through him or check out things like horses, carts, etc., but he had issues when the items you checked did not get returned in good condition or not at all. Which sometimes resulted in him denying requests. One way around that was gaining his favor. The Warrior brought the QM trophies from the various adventures. This favor gained enough that the group had to order new equipment (long story) and the QM got everyone One Masterwork item for free.