Worst experience ever using MX123. I will NEVER be using this site/service again.
I had a few dvds and video games I sold to them that were in near mint condition. 3 of them were rejected for no apparent reason (asked why but no reply). I also recommended them on social media for a bonus, which was confirmed by one of their representatives (Chris), but I never received it. Emailed/called them to try to sort it out and could not get a response.
It seems mx123 only communicates when it is in their interest to. If you want to ask about recommending them on social media, sure they respond. If you want to ask about payment, order logistics, etc. you are out of luck.
Bottom line: this site is not worth it, many other better sites out there to sell your stuff. The people running this place are extremely unprofessional, and out to scam/cheat people in my opinion.