You can expect to pay big bucks for a factory folder (up to $400). Butler Creek makes a great folder in stainless or blue, but they're getting pricey too ($80-$125). The Butler Creek is an awesome design and very effective. Unless you're looking to increase the value of your Mini-14, stay away from the factory folder.
You'd have to check on the legalities of post ban rifles with folding stocks. But unless you expect a gastapo ninja team to push their way into your home, what difference does it make?