Walther makes good cheap, functional red dot's. So do Tasco, Burris, Bushnell, Redfield, etc, etc, etc. Tasco pro-points are under a hundred bucks, and i've hunted with those in the field. You'd be ok with one of those...
They make a variety of models in the pro point line. Just get one in the $100 range, and you won't get hurt.
EDIT: This one is $130 at Wal Mart:
This one is $60 bucks at Amazon.com:
Both are Tasco Pro Points, either will work, but the one for $130 is clearly nicer.