I thought of something that you might have missed. This is very particular to YC.
Perhaps you didn't realize, but a successful application to Y-Combinator gets an average investment from YC of $18k.
("Twice a year we invest a small amount of money (average $18k) in a large number of startups" http://ycombinator.com/.)
18,000 for the whole company.
Let's look at it if you don't have a "technical cofounder=coder" who is part of the team getting the 18,000.
Now you have to put some of the 18,000 toward coding.
Now it is generally acknowledged that the total cost to a company of a worker is about double the stated salary.
So, 18k will get you 9k worth of salary. But of course you have all kinds of miscellaneous expenses associated with setting up a company!
Like paying for hosting, or a space to work.
Maybe you can reduce ALL of your other expenses to 20% of the investment, so that you're left with 80% of the investment (a preposterously large amount) that you can use on a coder. This is 14.4k.
This equals a 7.2K of salary (remember, you double stated salary to get actual cost to your company).
This is how much coding you get for 7.2k.
0.09 years = 1.44 months at 60k annual salary rate, or
0.15 years = 1.08 months at 80k annaul salary rate, or
0.125 years = 0.9 months at 96k annual salary rate.
At forty hours, you are getting:
230 hours at 60k, or
172.8 hours at 80k or
144 hours at 96k.
This is two weeks of crunch development time. And this is if you can give 80% of your investment to an outside coder.
Does this sound reasonable?
Also bear in mind that contractors are more expensive than salaried positions. And, if you have no coder on board, in other words you need a complete architect and CTO, then you are looking at the very highest end of that range.
And all this is you spent 80% of your investment on an outside coder.
To me, it would seem fair to say that you have more like half of your investment that you can possibly spend up-front on an outside developer, bringing those numbers to...
143.75 hours at 60k, or
108 hours at 80k or
90 hours at 96k.
Do you think you can hire a guy to build your next eBay-of-x for you in 90-140 hours to the point where it GENERATES ENOUGH PROFIT FOR YOU TO KEEP PAYING HIM?
Absolutely out of the question.
This is why, in particular, the Y-C formula requires a technical cofounder as defined in this blog post.
It's very particular to YC, because they expect you to get a company off the ground for about as much as a traditional company would spend on office space rent in three or four months.
Y-Combinator's formula just doesn't work without a "technical co-founder" working for equity.
Entrepreneurship is simply not enough, when all you have is 18k to work with spread among every single cost the company will have, until it's profitable enough to pay for coders: who are very expensive.