Hi Jimmy, M625 S2 might appear once a while on the pre-owned market…. But M535 is brand new, so it is unlikely to pop up used for quite a spell.
The good news is that M535 is reasonably priced at $5900 per chassis. Depending on your speakers, you can drive them with one single unit, and perhaps later add a second one for bridged operations if you want even more authority.
In stereo mode, M535 yields 250W into 8 Ohms, doubling to 500W into 4 Ohms. In bridged mode, each unit outputs 900W.
G