GomerPile is right- no WASR can have a folding stock, bayonet lug, or threaded muzzle in Massachusetts. There is no such thing as a pre-ban WASR, no matter how much someone may tell you. Sure, there are dates on the front trunnions of WASRS that pre-date 1994, but those are Romanian build dates of the military rifles that the WASR was built from.
If you want a folder, you gotta find a preban AK to build off of. They typically run $1k+, unless you get lucky.
If you are ok with pinning folding stocks and muzzle brakes, you can go with a post-ban AK, too.
If you wanted to go with a 7.62x39 krink on the cheap, I'd look into buying a Romanian Drako and getting it tax stamped and built into a SBR. They're the cheapest ticket to the 7.62x39 short barrel world, and come built in Romania on a very nice AKM receiver. Otherwise the Yugo M92 is your only other ticket to the 7.62 krink family, and you'll likely have to either buy one or build one. And those parts kits don't come cheap.