Yes 10k in loot but this is less if ur in a co op situation and the 10k is probly just enough to replace the units you lost in battle if even that much.
After you take into account buying the non gold required resources from a friendly town (475 food per grand master or something like that + 500 gold? few hundred wood? replace the possible 1000's of stone you went through using dwarven cannoners?, and the cost to train a unit to lvl 5, throw in the fact that you may be co op so your competeing with the other guy to loot gold. I dont know when you get down to it do you even make a real profit in gold doing a hard seige like Makkada Orcish capital? If you do make any kind of profit is it worth it for an hour or more of ur time? You can just do territory view battles and not lose any units and make all profit no need to throw stone at the enemy. I can make 4k in a territory battle and make that amount in about 10 min or less with no risk of losing any units so the gold aspect of seige is almost of no value to a player in my mind.