Alison...I just went through something similar on a transaction...the seller (my client) gave me total grief over it and I ended up losing an otherwise great client/friend. 

The associations around here can charge anywhere from 0 to several hundred $$$ just for the docs. (the one I live in charges NOTHING).  Then at closing these companies charge an additional several hundred $$$ for administrative fees.  I always tell my sellers to expect $500 to $600 and be happy if it's less. I put this on the estimated net sheet when I take the listings (which they sign) with a plus and minus symbol behind the $500-$600, so the seller knows what to expect. 

On this particular deal we found out after an offer came in that there were TWO associations involved. Seller paid 2 association fees but had no clue they were different companies.  This is not uncommon in LV, but is not everywhere in LV either.  Well, both associations had their own set of HOA docs...so seller got socked twice.  Not only that but both associations charged a $200 administration fee at closing.  One of those associations used an online company www.condocerts.com where the seller or I went to download the docs (so there were no paper docs unless we printed them)...and that company charged an additional $50 for the use of condocerts.com!  My seller ended up calling the Dept of RE ombudsman, several TV stations, our state senator.  She was ticked big time because it cost her close to $1000 to 'get out of the association'...it's highway robbery in my opinion.   She had no one else to take it out on so it was my fault!  I hated losing a client/friendship over something like this...but that's her issue.