How much do Optimism and Arbitrum pay for posting data to Ethereum on a monthly basis?

We need a http://l2fees.info for these stats.

For optimism, the "L2 Economics" section of this dashboard by @msilb7 sounds like it may be what you're looking for

data @ op labs, building @optimism 🔴✨ | go /gators 🐊  | casts are my own things | msilb7.com

Co-Founder at sablier.com, and open-source developer. I have a broad range of interests, including longevity, epistemology, physics, and psychology.

Security at Optimism. Formerly built Umbra and more at ScopeLift

For optimism, the "L2 Economics" section of this dashboard by @msilb7 sounds like it may be what you're looking for https://dune.com/msilb7/l2-benchmarks

I know that optimism has paid the nft creators handsomely.  😜