I've been looking into tillers for larger garden this year.
Considering a Troy built or a Cub Cadet in the $700-$800 range. Cub Cadet (RT65) has good reviews at Home Depot website. Troy Built has counter rotating tines, Cub Cadet has reversible tines.
Alternatively, I have a couple of small tractors, a Ford 8N and a 26HP Kubota, the tillers for them are ~$1300 but a disk would be in my price range.