I started full timing 3 1/2 years ago. My costs are:
Home base lot: $75.00/month, plus electricity that averages $36.00/month over a year average. My lot is owned by my brother in law and is in a very small town in a residential area. Water/sewer/garbage is another $60.00/month. I would encourage anyone to look outside established campgrounds if you are looking for a less expensive place to "call home".
I have an external propane tank, 150 gallon, that I use for heat in the winter. Propane usage this past winter was worse than normal because of the very cold periods we had during January and February, but it is cheaper and a whole lot easier using this large tank than the 30 lb tanks in my 5'er.
I also have high speed internet here on my home base and it is $38.00/month except during the summer months when I put it on vacation hold.
During the summer I volunteer at a state park in Florida which is why my monthly electricity average is so low. I do leave my electricity on at my home base when I'm not here because the minimum bill is $15.45/month and they charge $50.00 to turn it back on and I must be here when they turn it back on so it can't be working when I arrive. It costs me about $10.00 extra to leave it one when I'm gone, but a lot more convenient for me.
Insurance approx $800.00/year for the 5'er. I don't remember what my pickup insurance is, but I would have it even if I wasn't RV'ing so I don't count that.
I do have a cell phone, but no home phone so there isn't much difference here.