I have been looking to get a MP5 type gun and on Gun Broker they range in price from $1400 to $4000.Big spread in price. Which company makes the best?

Couldn't say as I have no personal experience with that platform. However I would suggest buying here: Atlantic Firearms They have a reputation of bending over backwards for customers if there are issues with a gun they sell. I got a discount for being a member of a certain forum when I bought an AMD-65 from them. Gun had issues and needed to go back. They ate shipping both ways and sent my FFL a check to cover the additional transfer fee. When I had issues with the replacement AMD65 they were up the Manufacturer's ass to take care of me. Blane was really top notch and I cannot complain at all about my experience with Atlantic.