Earnest money deposit

Just heard back from the seller on my offer and am meeting this afternoon to discuss some points in the contract. One of these is the earnest money deposit.

I had $3000 for the amount, and seller came back and requested $27000 (5% of purchase price) to “show I was serious”. That seems quite excessive to me- am I off base here?

Of course I’d rather not tie up that money at this point, and the contract allows me to cancel during DD for any reason with full refund of deposit so I don’t see how the amount of deposit has anything to do with how serious my offer is.

Any suggestions on negotiating this down?