How is a Tron energy rental price chosen?

Short answer

You name an amount and a duration. The price is the lowest offer that can fill it right then. You do not send a price of your own, and you do not pick a seller. For one USDT transfer the amount is 65,000 or 131,000. A bigger pack, or a longer duration, is used only when it still costs less than burning the energy you asked for.

The morning price list is already wrong

Open three Tron energy rental sites and you will often see three numbers for "65,000 for an hour." Some of those numbers were copied onto the page hours ago. The desks behind them move. A price that was the cheapest at breakfast can be ordinary by the time you pay.

gasrent asks when you ask. Several sellers answer, and you are shown one figure: the cheapest fill that is actually allowed. The others are dropped before the response. Ask again in a minute and it can be a different number, because the offers moved. That is the whole product. The Tron energy rental on the public site is this floor, not an average and not a curated shortlist.

You pay it from TRX already on the account. There is no card inside the order. The account is an email and a code, without a KYC step. What lands on-chain is a delegation of energy to the address you named, for the duration you bought. The seller does not receive your USDT and does not get a key. They lend resource. When the rental ends, the resource goes back.

Which offer is allowed to win

A quote collects those offers and does not charge you. An order collects them again, still with no price in the request, tries the lowest one first, and price_trx is whatever that fill actually cost. The two can differ if the market moved between them. If you need to know the number before you commit, quote first.

Not every answer from a seller is eligible, which is the part that keeps "lowest" from meaning "a huge pack you did not ask for, because it was cheap per unit and expensive in total."

The duration has to be 15m, 1h, 1d, or 3d. Leave the exact flag off and a longer duration may qualify. A shorter one will not. Turn it on and only your duration qualifies. Volume works the same way between 65,000 and 4,000,000: larger is allowed, smaller is not, unless you demanded the exact integer. A larger volume or a longer duration is then thrown out if its energy price, before any activation fee, is above the TRX the network would burn for the energy you requested. The comparison uses your request, not the bigger pack. A price that merely equals the burn is kept. You are not worse off than doing nothing.

If two offers cost the same, yours wins on volume first, then on duration. Sellers who only stock fixed packs are why the volume rule exists. Which duration is worth asking for is a separate decision from which duration a seller happens to have.

The burn in that test is your requested energy times the chain's sun price, divided by 1,000,000. At 100 sun, a request for 65,000 burns 6.500000 TRX, so that is the ceiling for a substitute pack. The transfer itself spends 64,285 or 130,285, but the ceiling follows the order you typed. A live energy price from the chain replaces the snapshot.

The order counts as filled when a confirmed energy delegation to that address is visible and covers at least 98% of what you ordered. Some other confirmed transaction sitting on the address does not count. If you are driving this from code, the same rules are what the energy rental API is doing. It is not a second price list.