Had Foremost for a dozen years while pulling a travel trailer. Insurance for the trailer, including full coverage with agreed upon replacement cost, generally in the $15K range, and full road service/towing, typically ran $320 a year. Foremost is quite different than an AAA policy. They do what it takes to get your RV and tow vehicle where it needs to go, not limited to X # of miles. When I first signed on, I asked how honest it was to claim that they had no dollar amount on towing? The rep. told me they had just flat bedded a damaged fifth wheel off the Haul road (The Dalton highway from north of Fairbanks to the Arctic ocean) at a cost of $3500, it didn't cost the camper owner a penny. Since then, they paid a few hundred bucks to tow my trailer and truck into a small town, when the alternator puked. It didn't cost me a dime. Just "sign the work order, and have a nice day"
We then switched to a motorhome, and added it to out auto policy, since it was shockingly cheap, compared to a stand alone policy. For road service we went to with Coach-Net. They are reasonable, and if you surf the RV forums, they consistently are praised as an excellent company to do business with. They cover motorhomes and trailers, btw.
As for doing business with Good Sam, I would really approach it with caution, and research first. Good Sam is part of a giant RV industry mega-corp. that owns Camping World. I have a GS membership strictly to save money with discounts at some campgrounds, and if I need something at Camping World. That said, they are extremely aggressive in their marketing. If you don't have an online account with them they will FLOOD your snail-mail with enough crap to keep a campfire going for days. The only way I can even tolerate them is to go online and opt. out of every offer to contact me in any way. Even then, if Camping World harvests your address, they will then start another avalanche of junkmail. As for their insurance. I found it to be a joke. I got one quote from them, back when we had Foremost, and GS was well over double the price. IMHO, the whole company is best avoided. They are aggressive, slick marketers, their products and services at the Camping World chain are not only extremely expensive, but they leave a trail of really unhappy customers, and lots of negative reports on the RV forums. I have gotten some good deals at CW, but I have also walked out, went across the street to Wal-Mart and bought the same product for 30-50% less.