No clue given the current economic situation what is acceptable. Sounds like it's way too much, what is the MSRP on this vehicle? You can look up the config on edmunds.com and get the invoice price. Basically in this economy they should be begging you for a sale so see whatever it is should be at or under invoice + dest and tax. What is tax in your area? Gives us more info if you want some real help.
Sounds high to me too. You're knocking on the door of a base MS3 (23-24K). I would want that to be much closer to 20-21K. Remember, YOU are in control, not them.
I just bought a 2009 Mazda 3 5 door Touring for $18K. Not including Tax, Tags, etc... I bought it thru Costco Auto Buyers Program. Definitely look into that first. If the dealer doesn't participate with Costco, they usually will match it to earn your business.