I sold all of my RF lenses for Leica RF within one month, with loss and purchased old new stock Summarit 35 2.5 two weeks ago. It was loss in money, but I have no regrets for paying to try many lenses before I was sure which and only lens to get.
It is really very personal. Some are happy within your money budget at 35mm range with old Japanese or modern Skopar. I didn't even bother with first and spend about three years and many meters with two versions of the second.
If you are taking it in color, Skopar is great. It is called Color Skopar for it. And it is not bw lens, IMHO. It is most flat and over contrast lens I used. But I used it a lot, anyway because of the budget.
40mm is not 35mm, period. If you don't want good framing, get it. Even Summicrons might be within your limit, because it is less desirable focal length, I guess.
Here is no cheap solution and good RF lens for me under low budget as yours.
Except.... LTM Ultron 35 1.7 ASPH, where you might pay little extra to get correct M-mount adapter, which aren't cheap. Very good, free of old optics problems lens. If you are bw. The build is so-so, but the lens is fixable. The reason I sold it ... Tables lens is not for me.