I'm not sure how well the auction is advertised to the public. Perhaps it is just offered to people in attendance? You may have a chance.
But if it goes to a national online bidding site, it doesn't sound like $500 will get you very far. Folks seem to bid full retail on most items, even ignoring the 15-25% premium, plus shipping and transfer fees.
Sounds like both Berettas are model 1935, 7,65 cal.
At a nationwide auction, assuming VG+ condition, and from your post-inspection descriptions, here are my estimates:
1: Sauer 38H Police, $7-800
2. Sauer 38H Civilian $450-550
3. Sauer 38H postwar $350-450
4. Beretta 4/UT $6-700
5. Beretta (unknown) ???? General Italianarmy are $350-450
6. Walther PP $6-700
I think you may need to step up to get the ones you desire, if you are able. Good luck.