I'm checking out Ezstamp first. Data entry seems pretty easy, although for pricing it lists mint and used, you have to manually enter a percentage increase for NH, which seems a pain, especially when I only collect NH (except the really rare ones of course

.) Although pricing is not the main focus of why I keep an inventory.
I'm thinking that I'll probably only use one of these (if I go that way) for my new US collection, rather than entering my existing Australian and Victoria collections. Especially since they base their catalogue on Scott, which frankly sucks for Victoria

. I know you can manually create new catalogue numbers, but when there's one Scott # for sometimes around 12 different stamps, seems a lot of additional work. I may as well keep the database I've created for them. Since I don't have any US stamps yet, it won't be an issue having to enter an existing basic collection, I'll just do it as I get them.
I'll let you know what I think of each of the software programs.
Balf