Yes, indeed the certificate cost is too high. Having in mind that LR is NOT as complicated as PS at all (regardless of all little things usually people tend to NOT use). I myself just as you retired the IT and went into the oversaturated photography market and still believe there's some place for me to contribute.
The question as you quite well pinpointed is if I would plan on caching from my contribution, because so far I see no real direct $180 fee return. However the reputation and image-wise it seems a good reason (to me at least). One-time fee might be better than spending so much more time on the Adobe forums in order to deserve a community professional. I am more into supporting the developers in debugging than into explaining common things easily resolved on youtube or google. I feel I can contribute better that way ;-) That doesn't mean I don't provide feedback when I find a solution to my own problems or thank to someone else's efforts.
Ergo one-time fee could be a good cheat. Might be wrong. Love to hear more pro-against arguments. Still haven't decided and besides - there seems to be no link to such LR certificate at the moment ;-)