I do this professionally, so my pricing may not be in line with how you feel about charging a friend...
I'm not sure what you mean by arts and crafts style curtains, but first let me just say that if everyone could do this they wouldn't need us and we deserve be paid well for our time, knowledge and talent!
Typically I will charge $35 - $50 per width (single panel) for simple rod pocket drapes, $45 - $65 for pinch pleat.. all drapes are lined unless it's sheer fabric.. Customer pays for fabric, lining, and any trim, pricing is strictly for labor.
Price varies according to:
Finished length - extra long drapes are always priced higher
Type of fabric - how fussy it is to work with
Embellishments - trims added at leading edges or at bottom
Any kind of bells and whistles that add to time and difficulty of job
This should give you an idea of what they should reasonably expect to pay. I'm in south Florida, there is a lot of custom work in this area and also quite a bit of competition.. My pricing is very competitive - not too high, not too low..
Another way to calculate your price, which I do for odd requests that don't have a set price, is to decide what your time is worth, on an hourly basis, and charge that for your estimated hours plus the expenses for supplies. Only you know what your time is worth to you - will you work for $5 an hour, $10, $35, etc.
A few tips -
Never underestimate the value of your skill
Never assume it will be easy, you may estimate 10 hrs and run into snags which could double the time
If you price low and get referrals from the job to do others, it may be difficult to charge more appropriately the next time
Hope this helps!
Suzanne
http://sjonescustomdrapes.com