Listen, I'm not trying to be 'stuck up' or to flame you.

I simply cannot comprehend why you wouldn't just pay a designer from the get-go, especially if you have a large enough budget for advertising, as opposed to him taking some of the profits.

If you have a large budget, then why not do that?

If your site has a guaranteed business plan, wouldn't it be more fiscal to pay him a few hundred now, instead of paying thousands in profits over time? (If this business plan is indeed going to work)

Not only would you get a better design, you'd be making more money in the future (as opposed to you both combined. losing 33% of your profit each month).