Yea, I kind of figured it wouldn't make sense financially, horses don't tend to. But that's more of a Dad thing. He's not big into spending money, and I've always wanted to try gentling a mustang, so, why not try? But he's already said that any kind of "incentive" the government has is not likely to be profitable.
I still think it's a great idea, though, and valuable experience!
Anyway, as for the training, it wouldn't be "just gentling" if I could help it. It's so much easier to train a horse that trusts you! Although, I don't really know how a mustang differs from a domesticated colt. The 2 colts I have trained to ride were handled in foalhood, then put to pasture. It took several weeks to teach them to lead, pick up there feet, saddle, and mount. Actually, I only put the first rides on one of them. Very quiet boy. (Tried to scratch his nose with his back hoof the first time I was on him!) The rest of the work I did by myself. I think I did pretty well for a beginning trainer. I also "trained" my horse Dusty to ride, but he has such a lazy temperament that he hardly thinks bucking is worth the trouble, so he barely counts. I expect a mustang would be a bit more active!
That said, I know I am not really qualified to train a horse in the saddle. Not for other people, anyway. Although, if I thought the horse was ready, I might sneak a ride... Hey, you have to start somewhere! ;) just kidding!