You need to get a person with mechanical and electrical skills to go with you. Miles and hours are not your issue, rather how was it maintained the past 12 years. If that is not practical, find an RV specialist in the area of purchase, check him out in advance. Pay him to do a PDI. Find out who holds TITLE and ensure it is free of liens. Never, ever, put $$ on anything that you have not seen original title. Liens take preference and if you buy, it's buyer beware.
Deposits are difficult to get back unless you have a signed contract ( acknowledged by both parties ) which specifies exact terms and conditions and time frames ( dates ) of action.
Take your time and do not let your enthusiasm outpace your wallet!!
There are thousands of used RV's for sale.