What do you want it for?
Something to shoot beer cans with?
Play against a friend?
it depends what you want the gun to do, only then can we help you "pick a gun"
but to answer your questions, there are currently no walk in stores for airsoft guns of high quality. And guns can cost anywhere from $5 for a springer to $5000 for a custom rifle, but the typical airsoft gun is a Tokyo Marui and it runs anywhere from 350/450 used to 450-550 new.
"I feel no emotion, just recoil."