A question: Are you able to sell the "left overs" and get back some of your money?
One must keep in mind, that every Crypto transaction has a Fee attached to it.
Someone, must do the work to process the Blockchain and that is where you get the, mining of crypto from.
when you Mine Crypto, you spend CPU or GPU cycles and Electricity to do all the Math to calculate the New Block Chain, and for that service you are rewarded with coin.
When you figure it all out, small time Miners barely break even, or they might even end up with a loss.
They spend more on Electricity, than they make on the process.
So where does that coin come from to pay the Miner? The person making the transaction pays for it as a fee.
On the ETH network it was/ is called a GAS fee.
And it has been Very High.
So no matter which way you go.
Buy ETH or Sell ETH the fee to do so was very high.
But even Higher when you traded ETH for something else.
Also, you have to have enough coin in your wallet to pay the GAS fee.
if you initiate a transaction, and run out of GAS in the middle of the transaction.
your transaction fails, but the GAS used up to the Point of failure is Lost.
So if the gas needed was 25.00 ETH, but you only had 20.00 ETH.
you'd loose your 20.00 ETH and the transaction would fail.
Also, you can get Bids that let you know how much GAS you will have to Pay, and select from the low Bidder.
Or you can put you transaction up for Bid, with a GAS fee limit.
But just because you accept a Bid, does not Guarantee that your Transaction will succeed.
you might still run out of GAS, and end up with a failed Transaction.
Best to always go with the Estimated GAS fee needed, than to Low BID on the GAS.
if someone with more crypto experience finds anything her incorrect,
Please post a correction.
this is all based on my past 5 years of Crypto Investing
( which tanked in the end of 2021 and early 2022 and I pretty much Lost everything. )