If you're going to go 7.62x39, you can get a SKS or an AK clone for less money. The MSRP for a mini-30 is $809, you can get a Yugoslavian SKS for $179, or a Hungarian or Romanian AK for around $4-500. I'm not an AK guy, so look around for better info.
Absolutely.
Look into a (Romanian) WASR-10 (semi-auto AK-47 knock-off). Chrome lined, and very reliable. Mine was $350.
SKS rifles (should) run less.
Personally, I'd avoid the Yugoslavian SKS rifles. They're not chrome lined.
You can find a bunch of info on both the SKS and AK/AKM here: http://www.surplusrifle.com/index.asp