As a rule, cheap high-magnification scopes are useless, due to poor resolution, the eye relief issue noted, and focus and depth of field issues.
There are a lot of very good inexpensive scopes in 3-9x due to the popularity of that range with US hunters, and some (but not as many) 4-12x scopes for the same reason. I would look at the Vortex, Weaver, Redfield, and Nikon options in those ranges for the lowest priced scopes that are worth owning. The Weaver 6x38mm (fixed) is also very good and is $150 or less when they go on sale at Midway every 3-6 months.
If you must have a lot of magnification, the Simmons 6-20x50mm scope that is a Midway exclusive goes on sale every couple months for $110-125 (two reticle options). I had one that I got with a used rifle, and it was tolerable, though not in the same class as the better 3-9x scopes in the $150 range. FWIW, adequate scope rings to mount a scope that big will cost $30-50 for just the rings, so big high magnification scopes are not a cheap game.