Any MP5 I've come across that is already in state is typically priced like it is a it's gilded in gold and diamonds. I've never looked them up online myself, so maybe that's something I should start pricing out. That's my dream gun.
Was in the same boat last year. Something about coming of age in the 90's and seeing the MP5 in all the action movies. Gun is cool as hell.
You're MUCH MUCH better off getting a good clone. They are way cheaper, many of them are built on old HK machinery or identical copies, and several manufacturers are actually regarded as BETTER than the original.
It's tricky to get in MA, but doable. Shoot me a PM if you wanna know how I got mine. Ran less than $2k, but needs a stamp.