If it's a '74 they've swapped out the front rotor because the '74 rotor was not drilled.
First thing I'd do is pull the throw out bearing, inspect it and lube it if it looks good.
Those bike also need an annual lubing of the transmission input splines to stave off the possibility of stripping them out.
Rotor is a weak link in the charging system, though it took nearly 9 years for mine to bite the bullet.
Front brake is weak, and I'd suggest upgrading to a stainless line to get better feel. It'll always be weak though, unless you upgrade to a second rotor, or upgrade the whole front end to a 80's model year.
No real gotcha's, but there's definitely some maintenance that these bikes need on a regular basis. It's not going to be like owning the Night Hawk or the k75 that you had.
2600$ is probably in the ball park. Got an R90/6 many years ago for 2800 that needed immediate trans work.