It would've been difficult to spend a two thousand dollars on RV solar system these days, unless this includes the labor. In parts, 700W system - hard to fit more on the roof - will cost around $1,300-1,500 including inverter and all the wires. Not including batteries - this is a separate subject, and often people already have enough batts.
What people sometimes don't realize is that $400 may get them a 300-350W system that would cover most of their offgrid needs - or all the needs, depending on lifestyle. It does require some work to install, but it will cover pretty much all your needs, other than air conditioner, and possibly - microwave (MW would require a better inverter = more $). You would be able to camp in the middle of nowhere, or stay in cheaper camps without hookups. 45W system doesn't come even close.