Sorry, to not reply earlier, Bill. I decided not to follow through with the purchase of one additional year on the warranty and it slipped my mind.
I found out from a dealer whom I trust that BRP currently charges a dealer about $322 for one year of BEST warranty. It does not matter if the the owner already has the warranty and just wants to extend it an additional year, or if the owner just wants to buy one year of coverage. (The more years you buy at one time, the less expensive it is "per year" of coverage.)
In addition, I learned that unless you buy your BEST warranty within so many months of the purchase of your Spyder, there is also a $70 "contract fee" that BRP adds to the cost. Even though I got two years coverage at the time of purchase, I would still have to pay the "contract fee" at this point to add another year. So the total dealer cost would be just under $400 for that one year. (My dealer offered to sell it to me for $450, which I thought was fair.)
The reason I decided against purchasing another year for my existing Best Warranty was two-fold. First that seems like a lot of money to extend the warranty just one more year, when I still have 18 months left on it. Secondly, I had removed the catalytic converter as a means of dealing with the excess heat on my 2013 RTL prior to the heat recall last summer. As a result, BRP knows that I did this and has tagged my existing warranty with this information. While this information would not VOID my warranty, or prevent me from extending it another year, if I chose to do so, it could possibly have the effect of giving BRP an "out" to deny a major engine claim, should they be looking for an "out". I'm not saying that would happen, but it is just another reason that I chose not to pay over $400 to extend my warranty for just one more year (which is the most I could have purchased). (If I change my mind, I can still purchase that one additional year, at the same price, anytime within the next 18 months, while my existing coverage is still in effect, UNLESS BRP raises the cost to the dealer.)
PS... I appreciate all the recommendations that folks gave me in this thread. I did not specifically call Bert's Mega Mall, or Pitbull Powersports for a quote, but I did get a PM from David at Sierra Cycles in Sierra Vista, AZ who did offer me a VERY attractive price for a one year extension. I would definately recomend a call to them if anyone wants to buy or extend a BEST warranty policy.