Say whether any key still starts it.
A working spare can change the work involved. If every key is missing, say so at the start. Have the year, make and model ready, along with the actual place where the car is parked.
Compare functions, not only the case.
A blade, starting chip and remote buttons have different jobs. Ask whether the replacement quote includes the necessary cutting, programming and functions for your vehicle.
Ask before using a part you bought.
Keep the listing, part information and packaging. A provider may be unable to use an unsuitable or previously configured fob. Check this before arranging a visit, rather than assuming a matching shell is enough.
Add the practical costs.
Compare travel, towing and any other quoted charges as well as the key itself. There is no universal cheapest route. Confirm authorization requirements and test the agreed functions before considering the job complete.