What matters is what's fair to you. The company will take care of itself.
Consider how much it costs you to operate your car. I'm not talking about the IRS figure of 57.5 cents per mile, I'm talking about your actual additional expense to operate your car to do this shop. Expenses such as depreciation, insurance, tags, etc. are going to happen whether I shop or not so I don't figure them when I calculate what I need. Right now my gas cost alone is less than eight cents per mile. That will vary according to the price of gas and the gas consumption of your car. You can calculate annual oil changes and tire usage based on the miles you drive and add that to your gas cost. That will give you a pretty good idea of the REAL cost to drive to do that shop. If you don't do the shop and you stay home, your depreciation, insurance, tags, etc. will be unchanged and will go right on adding up.
Then consider how long it will take you to make the drive and figure out the value of your time. Add that to your calculated car cost and you have your base bonus amount. Ask whatever you like, but know that as long as you cover your base bonus amount you will be all right on the shop. Always ask for more than you want. You may get it, and if not they will probably counter offer.
Mary Davis Nowell. Based close to Fort Worth. Shopping Interstate 20 east and west, Interstate 35 north and south.