Before you sign the papers to buy your perfect rv why not wheel and deal for these items:
1)a second battery.
2)solar panel and controller
3)accumulator tank
The rv comes with a new battery (it should) but if you camp at all you really need two.Get the second one now so they are a matched set.(most rv's have space for two).
Solar panels and controllers are pricey to buy later.A 100 watt unit will maintain your battery bank so you don't have to hassle with watching over it.Batteries last longer if kept charged up and solar controllers can do a better job than a regular battery charger.(and no extension cords...)
Shureflo makes your electric water pump.They also make an accumulator tank which mates to the pump.This pressurized reservoir holds about a cup of water.It's handy when you go to flush the toilet but forgot to turn on the pump.It's essential in that it quiets the plumbing noises of the pump and water pipes hammering when in use.Mum will love it.At about $75 the kit isn't expensive- the installation can be,though...and if they do it the job is guaranteed.
All in all,battery,cables,strap and solar panel,w/controller and accumulator you can figure about $800 to $1000.Installation could be $500 more.Before you sign on the dotted line,hand back the pen and say "let's make a deal."
I got half price on a new roof on a used trailer a few years back,I got 2 new batteries,my 2 old batteries and 2 solar panels with controllers installed on my recent trade-in.
And,if they smile and nod even if you offer to pay part of the bill consider more panels-nows the time!