Only you can decide if the cost makes sense to you.
BBB only has 4 customer reviews for "Discount ESP", so not enough for me to be comfortable with the results, but they only have 3 of 5 possible stars.
The dealer I bought from tried to sell me several different add-on policies. Some I rejected, some I agreed too.
The big one I paid for was something the dealer calls the Platinum Pit Pass Agreement. It covers the cost of all of the manufacturer scheduled maintenance for 36 months (with a long list of things that are covered, including fluids and filters), and guarantees priority scheduling for a service visit. That last part needs some explanation. My dealer does not accept scheduled service appointments, so you can't schedule ahead, show up at the scheduled time, and then wait for them to finish the service. Instead, their default is you drop it off and they'll call you when it's done, which can be a week or more, depending on how many other customers have dropped off their vehicles for service. They're a full CAN-AM shop, so long with Spyders and Rykers, they also sell and service all of the four wheel CAN-AM vehicles. The "priority scheduling" part is what sold me on the cost, as it means when I drop off my Spyder I'm immediately moved to the front of the waiting list for service. And yes, I'd still be behind any other "priority scheduling" vehicles that are already in line.