Even if you believe League One isn't any better than our league (which was kind of my point), I'll bet any one of the clubs mentioned pays at least double the fee we received based purely on the fact he's playing in England now. A fee they could have paid us directly for him when he was playing just as well and at a similar level of competition.
(Based on the English Championship games I watch most weeks, however, I'd say the the bottom half of that league is about SPFL level).
As for Belic, West Ham (I'm told) thought Belic would be a first team contender based on the fact that they thought SPFL football was a doddle. As it turned out, he wasn't even good enough to get a game for our U20s.