Sounds reasonable. Why not do it on a local basis and get links from all those local websites? Many people are still scared of the web and if they can deal locally youwill find it easier to win their confidence.
Depending on the exact widgets you'll be working with, this project could turn into a price guide sort of thing. I know that I have done Internet searches for specific objects in an attempt to see how old they are, and what they're worth. I've run across several that will show you the object, and then ask a fee to get current prices.
Particularly if your widgets are fairly unique, by using common sense SEO, you might end up with a lot of visitors.