You get what you pay for so don't buy a cheap set of rearsets, the quility of rearsets on the market aren't very good unless you spend a lot of money, I brought a set of Dunstall rearsets for my Commando back in the 80s, they lasted 6 months and had so much wear, they were flogged out and if I remember I payed a fair bit for them at the time.
On my Manxman caferacer project bike I am going to make my own rearsets, for the price of rearsets I think I can make a set better and stronger than the ones on the market.
Ashley