I got my pro one (Longacre I think) off of ebay... I think I paid $50 shipped for it. I have compared the HF to mine in store. The only noticable diff is that mine has a lot nicer gages... I suspect, if you wanted to turn your HF one into a really pro one you simply need to put some nice gages on it...
*shrug*
My used one did well enough to detect 100% leakage

I'll be using it again soon to check my rebuild

In this market there should be a lot of weekend racers unloading some nice stuff... unfortunately for them

You may be able to get a really nice part for not much $
Best regards,
Michael
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Michael 
'82 Euro SC 'Track Rat' 22/29 Hollows, 22/22 Tarrets, Full ERPB F/R, Rennline Tri Brace, Glass bumpers, Pro 2000's, 5 pts, blah blah blah
'13 Cayenne GTS