It's definitely technically difficult. You can't easily estimate how much an operation is going to cost before you kick off that operation, which means as soon as you get close to the limit you are at risk of tripping it.
Consider something like a "select * from bigtable" SQL query that might process a trillion rows. Hard to know that's going to cost $100 until after you have run it.
Consider something like a "select * from bigtable" SQL query that might process a trillion rows. Hard to know that's going to cost $100 until after you have run it.