Having owned a Mini for almost 10 years I think my input is worth what you're paying.

I got the Mini during the idiocy known as the Clinton presidency because I couldn't afford an AR. The AR vs Mini debate was a dead horse argument years ago, so we won't go there. My CMMG AR is one of, if not my favorite gun however I still have the Mini.

Personally, here is what I would do:

1) Get a varmint AR upper and scope it. Two pins and you're ready to go.
2) Build a varmint AR. The high grade kits are around $550 + $100-120 for a stripped lower and you have a varmint ar for about the price of a Mini.
3) Bolt action in the caliber of your choice.

BTW the term "assault rifle" pisses me off. Mine are all "anti-assault rifles" in that I am willing to use them to prevent my being assaulted.