Welcome to the best RV forums on the web...imho!!
Wow, I agree that you should tell this "professional" to go take a long walk off a short pier!!
In addition to the great advise in here, I'd also suggest you visit some local RV dealers where you live and chat with them and visit their maintenance department. Having a local contact to answer questions and look up prices has been a great help for us with our two campers we've owned. (Especially when you're out in the boonies camping and have a situation you've never seen and having someone to call for advise.)
Rick & Karen
(Retired USAF, MSgt)
5-year Travel Trailer RVers
2013 Forest River Rockwood Ultra-Lite 2904SS
2014 Toyota Tundra Maxcrew SR-5 TRD 4x4