What Happens
When Web/Cart/${sessionKey}/Tickets POSTing this endpoint if the request body is formed
```
{
"NumberOfSeats": 4,
"PerformanceId": 1,
"PriceType" : "1,1,2,3",
"Unseated": true
}
Where one of the PriceType ids doesn't exist the hangs for some time and then returns an error:
What Should Happen:
The returned error should be along the lines of 'PRICE_TYPE_DOES_NOT_EXIST' and reservation should fail. The error should be returned quickly.