Since there seems to be an ongoing race for boutique pedal to reach higher and higher prices, if I were looking at adding some effects on the cheap, I would go for pedals that fad-chasers are offloading on Reverb.com and the like. Maybe even look at modding some of the most common, cheaper pedals. There are tons of mods for the Boss DS-1 for example. Also, some old outdated digital reverbs and delays might have really bad algorithms for “normal” sounds, but maybe there is unique charm in that?
Amusingly, it does seem that if you have a simple off-the-shelf Boss pedal, you are somehow unique now, with everyone buying the same Strymon/Chase Bliss/Empress/etc. pedals.