Hopefully you're not under the impression that a motorcycle is a great investment and a money maker. This isnt going to be something you'll be able to spit shine, ride around until you're bored, flip it and make a few bucks. The bike is only worth what someone is willing to pay for it, and people buying Buells fall into 2 camps.
1. The guy who has $1500 and is looking for a cheap literbike to show off to his friends. This person is easy spot as they know nothing about the bike, except that its a cheap 1200cc sportbike.
2. Someone specifically looking for a Buell. This person has done their homework and is looking for something specific and usually in very good shape (and often willing to pay for it). This person is pretty rare, but their out there.
XB's have not hit the point of being collectible (and probably never will) and with parts supply drying up quickly, all its going to take is some random part not being available to turn it into a paperweight. The front isolator would be one of those parts. Luckily cvc and Twin motorcycles are working on replacements now. But what about the rear isolator? Belts for certain models are getting tricky to find also. The guys at the new Buell are only concerned about the 1190 platform and above.
As long as the motors not knocking, and all the parts are intact and not broken, $2K wouldnt be unreasonable. But if it does need a belt, tires, and other parts, that $2K bike could easily turn into a $3K purchase.