You did good!
Also, being a buyer and a seller on eBay, I make offers to people lower than what I am willing to pay "just in case" and I usually get a counter offer that is acceptable and often under what I would've paid. I have also countered back on offers made to me. It never hurts to make a counter offer, it's worth a try anyway in the future. Another thing I have learned is to not be hasty if the offer comes soon after item is listed as it may be worth more than you had thought. Give it time and make sure it has been "viewed" by several before accepting an offer. Good luck!!