First off, sorry to hear of your father's passing.

IMHO, selling them on sites like this or even in swap meets will probably not get you the best price (as others have already said, everyone is looking for a deal), but it will be the quickest and easiest way. If you want to get the best price, list them individually on eBay. This way, you don't need to try to determine a value, the market will set it for you. Yes, you might run the risk of something selling "on the cheap", but I have also seen bidding wars drive prices way above what would normally be sensible market values. In the end, you should net out with something very close to true market value. Of course, this is the most work too. Note: I know of at least one person who used to make make a bit of supplemental income by scouring classifieds, estate sales, and swap meets to find old kits on the cheap, then turning around and selling them on eBay for a profit.

In general, scale kits seem to command the highest values. I have seen Royal kits sell for incredibly high prices. Same with certain discontinued TF kits (like the Bonanza or the FW190). Do you have a list of kits?