And from my experience on the "agency" side, it's at most a minor speedbump.
Client wants us to do what? Oh, I found some tutorials online and there's a lot of StackOverflow posts on the topic. Also, Jim says he did something kinda like that about 5 years ago and thinks he still remembers some of it. Let's SWAG it at $200k estimate for T&M and see if they bite.
In the 5 years I worked at an engineering services (embedded systems) company, I remember exactly ONE project we didn't bid on and that's because I kept saying over and over that we'd lose our shirt on it if we even tried.
In my experience on the client side of a contracting relationship, that doesn't seem to give the agencies pause at all...
(As a sometimes consultant, though, I'd never bid on a project I couldn't confidently do.)