This is not the case, the price of unit decrease with volume and you can have a big discount if you want to commit to a yearly (similar to AWS/GCP/Azure)
I fail to see where you provided him wrong, based on my math and the calculator in the backend. The existing $29 is roughly equal to $240 on the new plan 250,000 operations vs 250,000 searches. Obviously operations include adding/updating/deleting data. But if you don't do any of that it's basically a different of $220. If you do some operations, say half of them are operations you are looking at $150~ vs $29.