because from what I've seen on Edmunds and Car Guru, the market rate
for this car is $23k
Congratulations. If the data is correct you found one that was lower than the average. That is the nature of the situation when the price for a car can't be fixed. Of course you still have to understand how much of a match there is between you and the ones that were used to calculate the average.
One unpopular option, or one unpopular configuration, or the selection of the unpopular color can mean that your car is actually overpriced at the amount they offered.
Also understand the role of a trade in and financing have in the negotiation. These two items can make the true price harder to know.
Make sure you understand how much other stuff they are including in their final price. Some items you can't escape (state sales tax), and others are dealer dependent (destination fee, dealer processing...).
You can always try and lower the price. They won't really be offended, though they may act like they are. It isn't an all or nothing negotiation, if you ask for a 2K lower price they don't throw away your phone number.