For what it's worth I just had Optimum here and they installed a new modem so we could get gig service.
Plugged it into my home network and nothing worked as the new modem is also a router and won't play nice with the network I have set up which is a router to a switch to ethernet ports and UniFi WiFi.
The tech had no clue how to configure the modem in bridge mode or disable WiFi and told me to contact Optimum. I did and after an hour trying to explain what I wanted, the magic words were "I just want the new modem to work like the old one", the tech recommended I get my own modem and confirmed the TM3402 works with Optimum.
So I know, cool story bro, but to make a long story short they're in stock at Amazon and I grabbed one.
Fair enough.
Ubee ubc1322 has a listing on ebay for about $57.
The others are: CM8200, TM3402, Netgear CM1100.
The CM8200 is what we have already looked at.
The TM3402 has just a few for about $80-$100. Amazon has it used for about $145-$150.
The Netgear on ebay is about $85 and up. On Amazon the New & Used has it for ~$100 and up, but it seems they have some speeds locked in?