That Bushnell Elite 3200 is probably as good of a deal as you will find for around $100. It normally goes for closer to $300, I would jump on it if I were you. Cheap optics generally are pretty bad. The Bushnell Elite line is a good value for the money.
What kind of problems are you having? Is it just large groups, or is your zero shifting?
I agree this sounds like a good deal and so does the Nikon for $149
Whatever if you decide on a scope, the Burris PEPR is a good mount and that will set you back another $80 or so.(I think they were $60 when I bought my first one). I prefer the PEPR mount over the similar RRA but one of those would work nice too.
The last scope I put on a AR has a Redfield 3-9x50 in a PEPR mount and it works decent. About 1.5" groups but that more to do with being a cheap pencil barrel (DPMS Oracle).
ETA- not sure what you have been using but a rifle rest of some sort is pretty essential to seeing what kind of accuracy the rifle is capable of.JME
