Shawn Domonsky commented on How to limit number of items a customer can purchase

Hello Mike, I hope everything is going well.  I may not have a direct answer for you but I think I can at least point you in the right direction.  If you check out the following link it can show you how to limit purchase quantities in your shop!

http://docs.shopify.com/support/your-store/orders/limiting-purchase-quantities

Good luck, I hope this helps! :)