Blackburn Rovers have a fantastic offer on their last 3 premiership matches of the season. Basically you can get an adult ticket for the matches against Wigan, West Brom, and Portsmouth for just £20, concessions are priced at £10.
I'm sure this must be the cheapest offer out there for Premiership football. Please don't vote this cold if you're a fan of another club.
Rovers offer adult season tickets from £249 and seem to be doing their best to attract fans to Ewood Park.