There are a lot of things that factor into that answer such as what is already there as far as age of the box, wire guage, meter, type of connection to main power lines, distance from connection to main power lines to meter box and then from meter box to RV stand, etc, etc. Also depends on what type of boxes you wish to upgrade to, BUT, for example I have been upgrading my lots to be able to use for a mobile home or for a RV and I pay approx. $1400 per lot. I also use the same electrician for all my work and so I get good prices for labor. My park is also in an area with generally lower labor costs than some. That $1400 is for a completely new installation. New pole, new boxes, new wiring.