>>3654103Get the 20. Sigma makes an Art 20 1.8 that is rated well, but I found it to ghost from internal reflections when pointed at points of light and in high contrast situations.
If you can work with 24mm, I have a Sigma 24 1.8 EX that I have fallen in love with. It's as good as the Nikkor 2.8 but with an extra stop and some change. I think I paid all of 200 for mine. You'll need a body with a built-in focus motor like the Df or older Nikon DSLRs but it works.
If you're set on ultra ultra wide, I have a Tamron 15-30 2.8 and I have seen the first revision of these lenses dip down to 700 dollars. It's a wonderful lens and very sharp, very contrasty but no filters. The spherical front element makes skies dark dark blue at the wide end, and it has a stabilizer which I've got down to 1/8th sec handheld on FF
>>3654085You can get a Df for 1500 now, that's 50% off when they were new. Pretty good deal for basically a D4 that doesn't do video
>>3654144I have, sometimes you get a better deal. Since I'm on a Df, I have access to vintage lenses that don't work on newer Nikons and I can buy them from antique shops. Pawn shops are also based you're helping the little guys out most of the time. I found my GoPro at a pawnshop and got a fantastic deal on it, a Hero 5 with the built in screen. Don't sleep on pawn shops, most of them don't carry camera shit but the ones that do sometimes have deals.