One set of boot spurs sold for $10,625. (He never used a set of spurs on Trigger.)
Nope. Not true. I have an 8x10 black and white autographed photo of Roy and Trigger that was given to me when I was five years old...59 years ago. Roy autographed it to me with "Always be good for Roy Rogers and Trigger."
It shows Trigger rearing with Roy giving him light pressure with the spurs. Below is another picture. If you look closely, Roy is cuing Trigger with light spur pressure again to make him rear.

When used properly, a large-roweled spur is not cruel or inhumane punishment. You are, in essence, rolling a wheel along its flank. On the other hand, a small-roweled spur is like goosing a horse with a screwdriver.
When leading a pack string, most packers will wear spurs...not to jab the horse, but in a dicey situation where the lead animal gets too close to a drop-off or edge, you need an immediate response in order to keep your whole pack string from going over. With most animals that are spur trained, they just have to hear the jingle to know that you are wearing spurs...then, when they feel the slightest bit of pressure from your calf, they move away from the edge p.d.q.
So...bottom line...it's no sin that Roy used spurs on Trigger. He used them properly...as a subtle cue, not an instrument of torture.