You can do at least 2k better. Go to RVDirect, spec out your preferences on the 28DSBH, and get your e-mail quote within 24 hrs. Use that to negotiate. Many, many people on here have done that.
Also, you need to search the web for pricing to help build your negotiating confidence. For example, go to
www.keystonervcenter.com, scroll all the way to the bottom, to the search function in the bottom right, enter 28dsbh in the keyword field, and you will see that they have 6 WH 28DSBH models for 22,408.