Average UK salary £25-30k.
A top of the scale school teacher outside London will be stuck on £35k forever unless they accept management responsibilities.
Ditto most ordinary professional jobs outside of the banking/law/accountancy sector, where they get yearly bonuses just for breathing LOL.
Think yourself lucky to be where you are at 36. I'm sure you've earned it. And if all you want is a bloke with the same salary as you there are places you can go to find one. And when you find him I'm sure that you will deserve each other if all you both care about is money.
However, I'm also old fashioned enough to think that a guy should pay the restaurant bill on a first date, no matter what his circumstances, purely as a gesture to indicate a willingness to invest, emotionally and otherwise, in a relationship with you. I think the lack of that sense of investment is what's really bugging you rather than exactly what he earns, at least I hope so.
Being a gentleman (which I think is what you want) is not about money, it's about outlook. So yes avoid the cheapskates and chancers, but don't dismiss an otherwise decent bloke just because he happens to earn half what you do - the fact is, most people in the country earn half what you do, and in many cases even less than that! Why do you think Aldi/Lidl are so popular? LOL
In other news, a little humility about the fact that you are fortunate wouldn't come amiss. Try, just as an experiment, living for a week on half your normal budget and then you'll start to realise why some of the blokes you meet who are your age haven't bought a house!
I bought my first house at 24 BUT at the time it cost 4x my salary. I was very lucky, and so were many people my age. You can't realistically expect most people to do that now because in most places that same house will cost 10x a normal salary and then some.
If he makes 1/2 what you do and if he still rents then that just makes him a normal person. And if you exclude anyone who fits that description then you might miss out on someone great, so focus instead on their education, responsibility, attitudes, GSOH, fitness etc rather than money. As in other areas of life, it's not what you've got it's what you do with it LOL.