This is a minor house rule, but it does ease the item acquisition process.

When my players try to acquire an item, I don't have them specify what quality they wish to purchase. Instead, I let them pick the quality after they roll their Influence check. For example, if a character tries to buy a stub automatic and succeeds by enough that they could purchase a Good quality auto instead, I let them do that. If they fail their test to buy a bionic arm by a couple points, I offer them a Poor quality version (a faulty arm is better than no arm at all).

This can be applied to nearly any system in equal measure.

But yes it seems like a good idea for the relatively minor change, especially in the situation you suggested.