So, I would say consider setting up your own company and doing independent consulting. That way you can just help companies out when they need it and continue to stay on the technical side of things. Depending on what your skills are, your rate as an independent consultant will probably exceed what you would make going into management anyway.
Not only do you get to deal with the increased costs (which claw back any increases), you also have an increased lack of stability for when things go wrong (which they will).
I've been doing nothing but contracts for almost 4 years now and almost every week a recruiter or someone is asking me if I'm available for a contract. I haven't noticed any age discrimination yet. I've seen guys in their 70's still working contracts along with me and doing fine.
You're disposable, so they like you - which is the problem at hand.