135i's are getting harder to find. I assume it's because the price on the small 'manual' BMW's keeps going up. The new M2 CS is selling for ~$25k over MSRP ($100k+). Everything below that is getting snatched up (and going for higher prices).
I'm kicking myself for not buying the 2016 M240i test drove 2 years ago. The price has skyrocketed since. I've looked for a good used 1 series, but they never seem to show up.