800 rds. for $200 is the same as 80 rds. for $20.
You know, division?
He probably used 800 in order to compare it to a case price which should be between $150-200 for 1000 rds. of M193.
At least you didn't waste too much money. [:)]
If you want plinking ammo, check out Aimsurplus.com. They have new production PMP ammo for a great price! As I said before, there are better deals on M193 out there as well. Don't worry, when I first got started, I paid too much for ammo as well!