What would be a cheap equivalent to the 50mm 1.8 on the 7D considering the crop sensor?
Like between a 24-28 would probably work but pretty cheap? Can be nikon or canon or any other but around 1.4-1.8?
For the crop sensor you'll need 28 or 30mm to achieve a "normal" 50mm equivalent. To get something fast will cost you... Sigma makes a 30mm 1.4 but its $450, Canon's 28mm 1.8 is about same. Sigma makes a 28mm 1.8 that is less expensive than the Canon or Nikon at around $350. Used can save you some but that's all I can suggest.
Maybe someone else around here knows of an inexpensive+fast russian or other com-bloc lens?