This sounds a lot like Line Tower Wars or Hero Line Tower Wars from Warcraft 3 (back in old days 
) or like Guild of Dungeoneering.
While i like your idea in general i need to ask a few questions or mention a few of my thoughts.
One of the things you mentioned is the reward/revenue system.
Iām not sure whether money alone is a sufficient incentive for playing or (more important) building and maintaining such a dungeon is. In āGuild of Dungeoneeringā you get a set of tools (mobs and obstacles) that you need to use to protect your dungeon against invaders (In this case the invaders are AI based). In your scenario there are freelancer (or other guilds) like to invade your dungeon but why should they do it ? If itās an easy dungeon there is no incentive to do it because everybody can do it and the reward is most likely really small (divided among all who master the dungeon). If the dungeon is to hard only a few will master it and the reward is most likely also very small because only few (good coordinated guilds / team of hardcore gamers) will try it. Iām sure we need some āhelpā from the devs (like a predefined reward based on the length and the used mobs of the dungeon - but this will cause problems too because the system might me miss-used or griefed). Do you have any plans according to the revenue problem ?
i hope you mean coins with ā$ā and not real money ?! If this game will consume real money for things (Items or Vanity) itās nearly dead for me. This was one of the game-breakers in GW2 for me (in early days ā¦ now there are a lot more).
If you need to maintain the dungeon you need a āreportā system like āYour dungeon has been mastered - Replace your mobsā otherwise the dungeon will be āemptyā from time to time. This would also be a problem if it should attract people ā¦ you donāt visit a āamusement parkā (theme park) if there are no āactiveā attractions.
The next thing i need to ask is how do you think to āscaleā for a different number of players or parties. Will you dungeon be instantiated (every party gets itās own dungeon) or do all play at the same time in the same dungeon ? Will it be harder for 5 player than for 10 players ? Will this effect the reward ? ā¦