I completely understand how scary it is for a first-time entrepreneur to consider such programs. The value is not obvious for beginners, so they tend to focus on the perceived low valuation (6% of your company for $6K is not valuing you much!).
But everyone who has been through such a program will tell you that the valuation (or lack thereof) is completely irrelevant. By becoming a Techstars alumni, you earn a label and a network.
Your average angel for instance is inundated with pitches from entrepreneurs. They need to apply a filter. Do you have paying customers? Come talk to me. Are you a Techstars alumni? Come talk to me.
You can spend 10 years of your life build your own network of connections. Or you can be selected by one of those incubators and jump ahead of the line. How much is that worth? Ask the guys at Udemy, they just raised $1M from top angels. Two years ago, no one would give them the time of day.
The last season they showed Boulder team, which had their demo day last month.
Funny fact: about the videos being compared to a reality show, the idea actually came from Hollywood, even though they produce it all by themselves (well, they do have Rackspace backening them...). Brad Field tells more: http://www.feld.com/wp/archives/2009/06/the-techstars-story-...
Raising is hard and quality advisors, warm introductions to investors, and simply being vetted and selected from a large pool of applicants will improve your chances of success (and therefore the valuation of the 94% of stock you retain) a lot more than the 6% of common you're giving up.