How do you price the WH? If it is a flat price then you do good on the easy ones and lose on the difficult one. If you do it by the hour, then you make the same as when you do a faucet. "Eat some labor"? Never! If the trim gets scratched it is because the faucet was badly corroded and that was the only way to take it apart. But, whatever time it takes to fix it, that is what is charged. You do not make "good" customers by losing money on them. All that gets you is a customer who expects a cheap job everytime and will dump you the first time you charge them the actual bill.