If it is in unaltered condition, $150 is a great price as far as collectors are concerned.
As a shooter, you'd be better served with a $150 Mosin.
FWIW, all 8mm's weren't created equal, and neither were all 8x57's.
This is so.
American commercial 8x57 ammo is pretty anemic, in deference to all the weaker guns chambered for it out there.
Milsurp amd European 8x57 is loaded much hotter..... would be bad ju-ju for an Gew88.
Here is some reading for those interested:
This used to be a separate site, IIRC ...... now run by yuku