I've had people ask me to sew for them, thinking I'll make them a suit for the price of the fabric. When I point out that they will end up with a handmade, tailored garment, just like the top name designers produce, and I would have to charge them designer prices, they're appalled! Then I just say "so that's why I only sew for myself"!
The range of prices for handmade quilts is EXTREMELY wide -- it looks to me like people charge whatever they think the market will bear! Search ETSY for the word 'Quilt', and take a look. I found this link for a crazy quilt for $4000! http://www.etsy.com/view_listing.php?listing_id=15671007&ref=sr...=tags&includes=title There are others listed for over $20K!
I've found that in rural areas where quilting is still considered a 'women's past-time', our time is not considered worth very much. In more urban areas, quilting may be considered more of an artform, so the artist's time and talent are valued more highly. Bottom line: do some research online, consider how close you are to the person, and decide if you want to charge for your talent and expertise, or are you doing the person a favor?