Whether or not you are up to it as DIY project, the parts will be in the $500-700 range, depending on how good a price you can get. If you have a major RV service place do it, you will likely pay retail on the parts and 2 to 4 hours labor.
When a manufacturer configures a model line for entry level pricing, that $10K savings compared to the competition is made up a few hundred here, a few hundred there. In the mirrors, you found one of the savings. A lot of the stuff, like fancier wheel "simulators" and dashboard trim, is cosmetic, but the power mirrors would be important to me.
The Velvac power mirrors come heated or not heated. You might save a little if you can do without the mirror heaters. I've never turned mine on, if there is frost covering the rig it will be parked in storage.
Tom Test
Itasca Spirit 29B