Foreign Investor Number to sell Mexico Timeshare?? legit?

Does anyone know if this is a scam or legit? Timeshare resale company is telling us we need to apply to a Foreign Investor number to be able to sell our timeshare in Cancun. Said we can obtain the number when we go to Mexico, (no plans to travel now) or they can obtain number for us for $$$. Anyone know for sure? I've search Mexican title, but do not find any reference to this. We are US citizens Thank you

If it's in Cancun, then you don't need a supposed resale company. If you find a buyer or taker for your unit, any transfer of ownership is done internally with the resort.

This smells like a scam all the way.

Thank you. What about needing to set up an escrow account in Mexico for the sale?? We have been scammed before, don't want to fall into a trap again.