That said: I'm not in love with the messaging here. The push/pull isn't between ineffective, inexpensive tools and ineffective, expensive consultants. Appsec teams are very effective. They just cost too much for startups.
My recommendation: stop positioning against security products and services. Nobody in the startup market really uses them and they don't care about their track records. Meanwhile, people in enterprise and large software markets are automatically wary of automated tools (like Appscan and WebInspect on the low end, or Veracode and Fortify on the high end).
You have a compelling story just by pitching the value of automated on-demand security testing at that price point. The direct comparison to competing tools just begs questions you don't want to answer.
(I've recommended Tinfoil to lots of people and continue to do so. Definitely glad they're finally launching!)