Re: Electrical issue
lets see, maybe $20 for the breaker and $40 for the box and $30 for the wire. $100 all told, but I did the work myself, and that does not include the right angle drill to drill down through the top plate of the wall of the house. I mounted my outlet box on the wall of the house near where I park the RV. Nice, because that's the room the main breaker panel is in, so not much of a wire run. Note that this is 50 amps, dual polarity, with 2 20 amp circuits, so a single polarity 30 amp setup should be rather cheaper.
Note that wire size is critical to avoid fires. You need to know the current AND the distance to ensure you use the appropriate wire. Also the appropriate type of wire and/or conduit depending on whether you are in a wall, exposed or under ground. Make sure your service will support this new large draw. I was originally only 100 amps, which would not have supported the new circuits. But I upgraded to 200 amps when I put in air conditioning, so it handles it fine.
If you don't know what you are doing, it is worth the effort to either learn, or hire someone who knows. Wrong wiring can burn down your house or kill someone. The hairiest part is installing the breaker. I'm too chicken to work in there with full power exposed like that, but fortunately I have an external main breaker so was able to completely kill the breaker panel when installing the breaker.
My suggestion is to put in 50 amps if you can. A bit more money, but can be easily converted to 30 amps. But if you put in 30 amps, you will need to completely redo it if you ever need to go to 50 amps. If you never will upgrade to a 50 amp RV or never will use more than 30 amps, then its probably not worth the extra. However, I use my RV as a 'guest house' and run the AC and that requires more than 30 amps.
I would suggest NOT putting 15 amp outlets in this circuit unless they are separately fused at 15 amps, either in the RV outlet box or from a separate breaker in the main box, with separate wire. This is because if you plug something into a 15 amp socket powered by a 50 or 30 amp breaker, then if there is a problem, something from the socket outwards is going to burn.