What about this:

Instead of offering a "stock" of parts or even a "stock" of predefined
kitted parts... offer a "part collection service." Someone who wants
to build a homebrew project could send you the schematic/article; you
would review the requirements and email them a quick quote on what it
would cost to provide the parts and the estimated time required. If
they approve, and order, you then collect the parts from your own
sources: some would be your "stock on hand", some would be orders you
place to other suppliers.

Advantage to buyer: one stop shopping; no need to spend hours going
over catalogs and going to different suppliers in order to get a pile
of parts together for a project. They dream of a project...they end up
with a bag-o-parts. It might take a little longer, and be a little
more expensive, to get the parts (because you might have to go find
some of them); but it will be a "turn key" operation for the buyer.

Advantage to you: You don't have to stock certain predefined "kits" or
go to the labor of building kits that might just sit on your shelf for
months. All you have to do is keep on hand a good range of basic parts
(that you pick up surplus, or on sale, when you can). In other words,
just keep a good "junk box" stock for yourself. If the customer needs
a part you don't have, then your cost to acquire it, and the delay, can
be figured into your quote.

Brad
WA5PSA