Well the Residential will run you from 1100 to 1800 depending what you want. Ours was 1100 on sale for a 22 cubic foot. Many like the Samsung RF197 which seem to be around 1400. You already have the inverter and four batteries so that's all done. If you hire someone to install it count on around 400 including trim work. The only thing else would be to decide if you intend to dry camp a lot. If do factor in another 600 to 900 dollars for a solar system. A 360 watt system would do but 500 would be excellent. Either way, once you go residential you'll never look back.
Good luck. Let us know how it turns out.