We have 270 watts of solar our our 19' travel trailer. Total cost was just under $1800 with us doing the installation. It can be done for a lot less but we wanted name brand equipment with long warranties and good reputations. Now we have clean, quiet power for at least the next 25 years... probably longer. I think the solar will outlast us - LOL. No gas to buy, no oil to change, nothing to load and unload, no worries about theft, etc. The drawback is I cannot run my A/C or microwave on solar but that doesn't bother me one bit.
Jerry n' Cynthia