1. Many clients prefer fixed price engagements, but savvy clients know that "prototype in 2 weeks for $5,000" isn't as good a proposition as it seems. What happens when I send you dozens of wireframes for a complex web app that would realistically take an experienced programmer a month to prototype well? Answer: I'm going to get what I paid for in real terms, but not what your offer really "promised" in spirit. Experienced clients tend to avoid one-size-fits-all offerings for this very reason, so you're left with the inexperienced clients who may wind up disappointed. These clients are easy prey, but can also cause real headaches as well.
2. Your Q&A section isn't very client-oriented. Yes, you're targeting the HN/"startup entrepreneur" set, which is comprised of people who might not think anything of answers like "That's not a question and this is also a prototype", but great service providers exhibit respect and humility. If you're interested in building prototypes and probably aren't going to want to go beyond that, "My primary focus is on building fantastic prototypes. Please inquire about non-prototype projects" would reflect a lot better on your attitude than "That depends on how interested I am in the project." Your clients pay you; you're not doing them any favors.
3. The idea "it shouldn't matter what language this is written in" sounds good on paper, but it is actually quite flimsy. Prototype code may be scrapped relatively quickly, but the idea that a client will build a prototype in two weeks and not want/need to iterate on it before building a production app is absolutely naive. You're basically saying that every assumption and use case that went into producing designs/wireframes will be dead on, and validation won't require any tweaks. If the client isn't willing to invest in Clojure and you're (likely) gone after $5,000 and 2 weeks, where does that leave the client? The better approach: if you're sticking exclusively with Clojure, sell the benefits of Clojure and leave it at that; don't try to fool the client into believing that "it shouldn't matter" because your code is supposed to be written once and then disposed of.
Bottom line: I don't know Chris and he may have great skill and experience, but this offering seems like little more than an angle for the developer to drum up $10,000+ monthly while making sure that he really doesn't have to align his interests with those of his clients. Wham bam thank you ma'am...