Was checking out gunbroker.com and found these.Sellers user name is KM1 he has glock 21 and 23 mags gen 3 high caps  10 for around $90.00.Add states they are used  but look pretty good in the pic.I purchased 10 and will post the condition when they arrive.Just thought id give a heads up.

Mags showed up today.They look like they have had little to no use.Area of the mag catch is nice and clean.No real sign of any use.For the $9.00 each I can live with that slight use issue

Just so you know, occassionaly Botactical has sales on glock mags for $12.95 brand new, latest generation.
Now, alot of people will tell you their customer service sucks, but every time I order mags on their sales, they come through.

YMMV