Hello. Welcome to NA.
You've come to the right place. There is a large community of knowlegable collectors here. You should be able to both get accurate price estimates and field offers to buy your items.
I'm very sorry to hear about your husband and I wish you good luck with all your sales.
Condition is everything with boxes. The first thing you should do is take a whole bunch of pictures of all your boxed games, including close-up pictures of the corners and any damage.
Post those pictures in the Price Check forum and people can give you accurate price estimates.
Note that you can easily get prices for loose carts by looking at completed eBay auctions or using
http://videogames.pricecharting.c...
After you have an idea of how much you want to sell you items for, you can create a For Sale/For Offer thread with a list of your items with pictures, and you can sell your items here without having to deal with eBay fees.
Good luck!