I've been trying to hire a tester for a few months without success. I really want to find someone who is both a tester and a developer, not because I want them to do two roles, but because the kind of testing I want them to do is all about automation and therefore I think they need to be able to at least programme in a scripting language like python to a reasonable level. Agencies tell me that it's not realistic to aim to find such a person, and I think their reasoning is something like: a good developer would rather be a developer than a tester (more money, more prestige).
So, my question is: is it realistic to try to find a developer turned tester or a tester who has learned to develop testing code? If not, what's a good alternative approach?
Edit: Great answers, guys. Thanks so much: this has been genuinely helpful. If anyone here is interested in a test automation development role based in London, let me know!