I just ordered a pair of rinehart slip ons, supposedly they are a bit loud. After reading about them, I'm a little worried they will be too loud, guess I'll find out soon enough.
I have drag pipes and they are loud on my bike.... I dont know the price of them tho but here is a clip out the pipes on my bike... The vid doesnt do them justice!
If you just want loud then cut the tips of your stock pipes off and gut them. J&P cycle has some nice slip on drag pipes for like $135 and they even have baffles if you want to tone them down some. If you want the bike to run and sound good then get a nice set of slip on's like the others have said.