It all depends on the boat you get. There are trade offs on almost everything. Very stable also means less maneuverable. Less money has a tendency to mean more weight and less versatile... or just cheap.
As for other things, what are you going to use it for? I've spent more on rigging and convenience than I did on the boat and it's not a cheap boat. The two most expensive items were a solar/GPS and a trailer. My boat is big and stable, so I can ocean fish when I want to and I take a lot of tackle most of the time. The trailer isn't necessary, but it sure makes life a lot easier.
Rod holders, anchor, drift sock, live bait system, etc... Again, what will you use it for?
Primarily just for bass fishing local lakes, once I get comfortable with it, I woulf like to take it out on some rivers for trout. Thats about it. I dont want a really heavy kayak as I dont intend to buy a trailer for it. I dont want one I'm going to flip over if I set a hook to hard on a bass either.