Well, if you consider it this way, then you get the 3 figs for 3$ (the usual deal), a horse usually worth 3$ (that's 12$ worth of figs for 10$) as well as a cart. It's as if they pay you 2$ for you to take the cart off their hands. But I suppose that the more you buy the better deal you get per fig, which still doesn't make sense considering the battle packs sell for their standard single-fig unit price. What I usually do with this set (I have several) is contribute the lion knight and dragon soldier to their various factions' infantries and taking the spear, captured lion soldier and horse and make an addition to the lion cavalry army. All in all, a good deal if you're looking to add to your fig collection then this is a good buy. 8/10.
If I were to make something out of LEGOs, I would probably use LEGOs. Pretty advanced stuff going on up in my head.