Field note
What a Crypto-to-Fiat Conversion Really Costs
“Cheapest” is not a trading-fee percentage. The amount of fiat that becomes usable depends on the offered price, explicit fees, withdrawal charges, custody exposure, settlement delay, failure risk, and records needed for tax and accounting.
That framework matters especially when comparing a live exchange with a protocol that is still a published architecture. PayMoney has no production price, fee, latency, or failure distribution to put in a comparison table yet.
Price and fee are different fields
In the PayMoney target, the maker commits one crypto quantity, one fiat currency, and one exact integer minor-unit amount. The protocol does not consult a rate feed, convert between USD, EUR, GBP, and PLN, or reprice the pair. A taker can compare that fixed pair with other available routes before claiming it.
A separate protocol fee and mandatory claim bond also exist. Their policies belong to the immutable deployment manifest and wallet display. The bond returns on successful settlement and pays the maker after an expired claim, so it is capital at risk rather than automatically a cost. None of those figures is defensible before measured policy exists.
Custody has a price even when the line item says zero
A centralized route temporarily turns the user's asset into a claim on an exchange and may add withdrawal review. A non-custodial route leaves the crypto in resource-owned escrow instead of a platform account, but shifts completion risk to the payer after the fiat transfer.
Those exposures are different, not absent. A useful comparison asks who controls value at every stage and what remedy exists if the expected next event never arrives.
Time is a distribution, not a promise
PayMoney's target needs direct MPC-TLS sessions, a two-of-three notary quorum, local or coordinated proof generation, epoch inclusion, and Ethereum confirmation. Network bandwidth and bank behavior can dominate. Any single “settles in N minutes” claim before real adapter measurements would be a guess.
Compare percentile completion times and failure rates from production evidence, not happy-path demos.
Exactness removes slippage and creates a hard failure edge
There is no tolerance band. The bank record must equal the offer's currency and integer minor-unit amount and match every other committed field. That removes rounding and overpayment semantics from the proof, but a mistaken irreversible transfer cannot be repaired by an operator.
The required wallet preflight is therefore part of the economic comparison: it reduces the chance of paying when the unique evidence path is already unavailable, but cannot eliminate a failure that starts later.
The honest comparison today
For a live route, collect the actual quote, fees, withdrawal amount, completion distribution, custody terms, and failure remedy. For PayMoney, evaluate the architecture and launch gates, not a fictional price. A fair cost comparison becomes possible only after a deployment publishes its fixed offers, fee policy, bond policy, supported adapters, and measured completion data.