depends what vertical you're after. i don't own one outright but i've run a few in the cc-submit space and the real bottleneck is never the offer, its the traffic source and the processor like the other guy said. if you want your own you basically need a dev, a processor that wont freak out at sweep volume, and a backend that can handle refunds without nuking your MID.
honestly for most people buying direct from an advertiser is overkill. you'd be better off finding a network that has an exclusive sweep and asking your AM to bump your payout once you prove volume. saves you the whole compliance headache.
what's the goal here... you trying to own the offer so you keep more margin, or just tired of caps and shaving on the affiliate side?