Sending ALL wallet balance not working well

[DavidOzan83]

Hi,
I'm trying to send the entire balance of a wallet to another wallet.
To do so, I'm calculating the estimated fees and decreasing them from the balance.
The issue is that I always get INSUFFICIENT_FUNDS, I believe it's due to the constantly changing gasPrice..
I was able to overcome this issue using maxFeePerGas for calculating the fees, but then I'm leaving around $0.3 every time.
Is there a way I can send the entire wallet balance such that it will loss $0, or at max $0.01?

PS:

my code:

    // get default provider
    let provider = ethers.getDefaultProvider();

    ...
    (some code)
    ...

    // Get the balance of the wallet.
    const balance = await provider.getBalance(my_wallet_address);

    // Calculate gas fee.
    const estimate_gas = await provider.estimateGas({
        from: my_wallet_address,
        to: to_address,
        value: balance
    });

    const gas_unit_price = (await provider.getFeeData()).gasPrice;
    // can overcome the issue using maxFeePerGas but then leaving some $ in the wallet
    // const gas_unit_price = (await provider.getFeeData()).maxFeePerGas;

    const gas_price = estimate_gas * gas_unit_price;

    // Make sure the balance is greater than the gas fee.
    if (balance < gas_price) {
        utils.error("Balance is not enough to cover gas fee, aborting...");
        return false;
    }

    // Calculate the maximum amount of Ether that can be sent by subtracting the gas fee from the balance.
    const max_amount = balance - gas_price;

    // Send the transaction.
    let res = await wallet.sendTransaction({
        from: my_wallet_address,
        to: to_address,
        value: max_amount ,
        gasLimit: estimate_gas
    });

[AFwcxx]

maxFeePerGas is a bit too high leftovers. One way I did was had to add 10% buffer to the gas price suggested by the provider. Won't be able to get to exactly 0 of course, but it's negligible.

const feeData = await provider.getFeeData();
const gasPriceBuffer = BigInt("10"); // Percent
const gasPrice = feeData.gasPrice + ((feeData.gasPrice * gasPriceBuffer) / BigInt("100"));
const gasCost = estimateGas * gasPrice;

[ricmoo]

Keep in mind, once we have EIP-3074 we’ll be able to trivially drain an account with no dust. If there is no hurry, I’ll put up a sample drain contract once it’s available. :)