Instead of placing an order for BTC in an exact amount of USD, you can place it for an exact amount of BTC then get a quote for the dollar price and transaction fee within Coinbase. Ordering this way is more convenient imo, but it’ll require the laboratory to quote you a fixed BTC charge instead of a fixed dollar charge. It also gives you the chance to order the ‘network fee’ in BTC for sending payment to the lab from the exchange without having to estimate it yourself in dollars (since this other fee is in BTC).
For extra security you may pay from your wallet, not from an account bearing your name listed in an exchange. Bear in mind that’ll cost you an additional network fee, i.e. from
exchange-to-wallet-to-lab as opposed to
exchange-to-lab.
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If only UGLs would drop BTC in favor of some stablecoin. Bitcoin is too volatile for sustainable trade of merchandise. Not to mention the blockchain is outdated, environmentally unviable, transactions are relatively expensive, and fucking slow. I don’t get where people come up with the idea of it being “digital gold.” It literally isn’t with the availability of other, actually more useful, alternatives. Pisses me off.