When I first read the post, I kinda guessed that might be what was going on.

Most shops use a "flat-rate manual" to determine an approximate time to charge on a given job. For both mechanical maintaince and body work these books can be fairly acurate. The rub comes in when the cars get older, as they don't take into account things like rusted/seized parts, previous damage, or other work that someone has cobbeled together.

You don't say wether the quarter is required because of damage or rust. Either can have other work involved to properly replace the quarter properly.

If it was me, I would take it to the body shop(s), have them look it over and explain exactly what they feel is required to properly do the repair and get a price on doing it. Most shops in my area now charge a nominal fee to do an estimate (refundable if the repair is done in that shop).

When you find a shop that you feel confortable with let them do the repair with the stipulation that once they get the old quarter off if more extensive work is required to call you before they do it.