The seller only allows buyers to purchase 10 items every 10 days.

[thisisall1word]

A buyer said they get this message when trying to buy 20 of these items:

https://www.ebay.com/itm/325295079221

I am sure there is some setting buried deep in the overly complicated selling platform. Anyone know offhand where it is?

[evry1nositswindy]

It's under account settings, probably under selling preferences.  I haven't looked for that in a long time!   You might have to click around to find it.  Or maybe someone else here will know right where it is.

Keep in mind that protection is for you.  You don't want a buyer getting 20 things from you and leaving 20 negatives (worst case scenario of course!).   

[nobody*s_perfect · Accepted solution]

Here's a link to your buyer requirements, where you can limit the number of items a member can purchase in 10 days:

https://www.ebay.com/bmgt/buyerrequirements