Is this from a dealer or pp? Check everywhere you can for pricing and options. As noted there are some dealers that sell cheap, particularly those in texas it would seem. As to the tow dolly is this with or without a vehicle included. what do you plan to tow? Tires are just the first of what needs to be checked but yes they are high $$ items to replace ($1500 or so). Since it is a C also check well for leaks and other issues.
I searched craigslist and found ours and hope you have also. Take a look to see how it stacks up aginast what you found.