I agree with GB. Given same quality, fixed scopes are less expensive than variable scopes. The reason for this is that there are more components in a variable scope than a fixed, which thus equates to more parts and labor.
While you can get a decent fixed scope for under $200, please don't think that $100 will do the job. I would imagine that variable scopes would cost approximately 25% more than a fixed scope. As such, and this is just my assumption, you could get a decent fixed scope for pobably no less than $150. :?
Again, we are not talking about GREAT scopes, just "decent" scopes.
Zachary