Well....

Since you bought it and it's all yours, of course it's a good deal.... Now that you bought a kit, you'll find it elsewhere cheaper but that's besides the point. Stick a film in it and see what you get. You might have some light leak issues and that's not unusual. You can buy a seal kit from Jon Goodman (who is a member here) and you can do it yourself.

I'm a bit concerned about the fungus if that is indeed fungus. It can eat the coating and etch permanent mark on surface. You might want to bring it to someone to get checked out. Just keep in mind, you can buy that lens relatively inexpensively from KEH and elsewhere if repair cost is going to be high.

Seriously, don't worry any more about the deal. It's already yours. Enjoy it and get the most out of it.

That's what I intend to do with my RB-SD.