I find these prices quite high for the time. Of course in the pre internet days helmets were a lot harder to find, but even allowing for that this is a very expensive price list. $300 for an M15 tschako? I bought an identical one in 2000 for $350. When I started working in the trades in 1974 a good carpenter made $5.00 an hour. $300 was a LOT of money.