Are you taking the whole bike in or just the forks? They shouldn't charge more than an hour for labor if they are off the bike. A stealer here quoted me $75 to change the seals on mine. That included the required fork oil change and spring replacement. This was taking the forks in though.
I ended up doing it myself. It took me about 2.5 hours from jacking up to lowerering down. I wouldn't pay more than 2.5 hours labor.
If the seals aren't leaking then I feel they don't need to be changed. If one is leaking, do both.
Keith