I agree the longer you keep the bike and put ample miles on it it starts being worthwhile to purchase an extended warranty. But again, there are so many costs associated w/ ownership even the odd big ticket item isn't that big a deal. Just total up the cost of everything mentioned in my post and even 2x $3,500 as bigger ticket items only represents 15% of the total cost of operation over 12y, which is about what I hope to get out of this RTW. I am definitely riding less miles/year as I age as well. If I paid for extended warranties over 9y of that 12y and did not have to pay for those two $3500 repairs now the cost of those repairs represents only 6% of the total cost of ownership since we coughed up $2500 for 9y worth of extended warranty coverage. And then there are repairs that will not be covered under some extended warranties when they define, for example, shocks as 'consumable' items, like tires, etc. And if we don't happen to have $7K worth of big ticket items by the time we get to 120K miles or 12y, now the total cost of operation goes down to $0.32/mile versus around $0.42/mile when you sell and buy new every 4y or so.
Here is how I look at the value of an extended warranty, cost of warranty v cost of repairs covered by the warranty. You had 2 3500 repairs that might have been covered by the warranty that is 7000 - in your case 2500 for warranty means you would have been 4500 richer over the period of the warranty.
In my case the warranty was I think 1250.00. Is it likely that I will have a covered repair greater than that amount over the life of the warranty, I will say yes so it is a good deal for me. Also the warranty has unlimited mileage when it kicks in, the average mileage on the last several vehicles I owned was over 200,000 miles, two of the vehicles were motorcycles. In each of the cases that I bought an extended warranty on a vehicle it has paid off for me. I suspect the reason is keeping the vehicle long enough to amass significant miles. In many cases an alternator, suspension component, or drive train issue like drive shaft or rear end will need replaced and be covered by the warranty. Often those components are expensive to repair and are more than the cost of the warranty.
For me it makes sense financially to spend the money. I also do not trade every 4 years but more like 8 to 12 years.