I am mostly a P.38 collector but this last year a number of WW2 Hi-Powers have taken up residence in my gun safes. I have paid $1000 or slightly less, each, for an "a" series fixed sight pistol and a "b" series with three-number stampings.
The Tangent sight models have been more. My WaA140 was +- $1200. My WaA103 was +- $1500 and my WaA613 was $2000( the mag is also WaA613). All are very good and matching but not "mint".
I originally bought them as "trade bait". That is, someone might have a P.38 variation I "need" and might want a Hi-Power more than they wanted the P.38. That could still happen but I have really enjoyed the pistols themselves as I have learned more about them.
Hope this helps!