Vintage lens options for my Canon or $500 Sigma?

[alfa147x]

I year ago I had an opportunity to sell most of my fancy gear and turn a nice profit. I sold following:

• Canon 5DII
• Sigma 50mm f/1.4 EX DG HSM
• Canon 24 - 105mm f/4 L
• Canon 50mm f/1.8

I rarely shoot anymore but when I do I hate my Canon EF-S 18-55mm f/3.5-5.6
It's horrible. Terrible. Undeserving of my 30D.

I was considering picking up the Sigma 30mm f/1.4 EX DC HSM or the Sigma 30mm f/1.4 DC HSM soon.
On my 5DII the Sigma 50mm almost never left the body. I loved it. I'm looking for something like that for my 30D.

The 30D is aging so I'll probably replace it in a year or two. When I do it will be a FF camera and (correct me if I'm wrong) Sigma's lenses marked "DC" are not FF friendly.

I'm considering picking up an old m42 lens and an adapter and trying that out. Any ideas?

Any other suggestions?

If I pick up an older lens I would like my first one to be around $50 - $70.

 

[yhelothar]

The Carl Zeiss Jena Flektogon 35mm F/2.4 M42 is legendary for that focal length.
I haven't seen comparisons with the sigma, but the color/contrast/bokeh is absolutely gorgeous on the Zeiss. It also has macro focus which is a bonus.