Well, you can go with a Marlin 795 semi-auto...costs around $129 or less.
They also have a $25 Manufacturer's rebate going on until Dec-31st, 2010, so that puts 'em in the $100 range
The 795 has a medium-weight tapered barrel, which tends to be a slight bit more precise than standard thin .22lr barrels. It is a heck of a bargain.
Or a nice used 25-series Marlin 25/25n/925/etc...usually $120 or less in pawn shops.
Same for the 80-series including the 880 SQ/980 Heavy Barrel rifles that put CZ's back on their haunches
Just about all of them have a 3/8" scope rail or D/T for rails/scope mounts, so you can slap a Center Point Scope or Red Dot for less than $75.
But for me, if you are gonna go .22 for varmints/small critters up to coyote size...might as well go .22 MAGNUM!!
A good Marlin 25MN or 980VS will outshoot any .22lr out there, and do it for low $$$ for the price of the rifle, even though the ammo is more expensive, plus it gives you out to 150 yards to blast something!!