Why Your Scroll Deployment Cost $25 — And Then $0.04 the Next Attempt

forge script returned an L1 fee estimate of roughly $25 to deploy a 6,452-byte contract on Scroll mainnet. L1 base fee at the time: 0.23 gwei — historically low. The wallet had ETH. The node rejected the transaction anyway. The next morning, the same contract deployed for $0.04 total. The 625× gap comes down to two parameters and who controls them. What the oracle returns Every Scroll transaction carries an L1 data fee on top of the L2 execution fee. The Curie hardfork (mainnet July 3, 2024) introduced this formula: l1Fee = (commitScalar × l1BaseFee + blobScalar × txDataLength × l1BlobBaseFee) / 1e9 Both parameters are in the L1GasPriceOracle contract at 0x5300000000000000000000000000000000000002 . Call getL1Fee(bytes calldata data) with your serialised transaction to see what Scroll will estimate. At peak: L1 base fee was 0.23 gwei, commitScalar was 6,195,200,000,000 . The oracle returned 15,216,334,956,613,434 wei — roughly $25. The math checks out. getL1Fee is an upper-bound estimat