A "Hack" for limiting the amount of tickets a person can purchase on TNEW

We have a TNEW Dropdown limit set at 8 tickets for our general museum admission, but we kept having people go back and add 8 more, then 8 more, etc. Often these were child tickets with no adults added to the order from summer camps. After looking at the documentation and even the ticket limit plugin, we came up with our own way to fix it. We created a price type called "Too Many Tickets" that isn't assigned to any MOS or User Group. Then we set up a pricing rule where if more than 8 tickets were added to a cart for the same day of general admission, the price type would flip to the "Too Many Tickets" price type. Because that price type isn't assigned to any MOS or User Group, it breaks the TNEW session, clears the cart, logs out the customer, and displays an error message. We have edited this error message to have the customer call our box office, where we can direct them to our group sales as needed. I hadn't seen anyone else do a similar workaround, so I'm posting it here. 
-Jane