i have a very old one at FloorSkills a customer has dropped off and asked us to sell on (they have retired) . It is one of the first ones, no lock and head is fixed. Nothing wrong with it tho, it does the job it was designed to do. It is very heavy which is a down side. The chap selling it wants somewhere around £200 for it. Open to offers tho. It is collection ONLY. If you want it you can view first and even try it for your self @ floorSkills training centre.
Might have a power stretcher available soon, not seen it yet so not sure if it's light or heavy, fixed head or not...
I got one brand new less than 2weeks ago. Their heavy 62lbs. Unless you get one with alloy tubes but have never seen any advertised with them as standard. You can buy alloy tubes as extras. The one I got was in one case, you can buy 2 case sets ( one power head and one extension tubes).