I am absolutely thrilled with my Miller 140 Auto-Set. http://www.millerwelds.com/products/mig/product.php?model=M00234
I know I didn't need to spend that much, but I wanted a good reliable machine that was supported by my local welding supply store.
You can figure on an additional +/- $150 if you buy your own bottle of shielding gas. I have never welded with flux core wire. (and never will)