Almost certainly...
They will tell you that there are no upfront fees, but after they have you good and hooked, one or more (completely bogus) fees will pop up.
The may call it Mexican taxes, real estate fees, transfer fees, title search, title fees, escrow fees, blah, blah, blah.
They may even show you some documents that they have created to "prove" that these fees are legitimate and really do have to be paid.
They will assure you that all you have to do is pay the fees, to get your big fat check.
They will tell you that the fees are going to be sent to a reputable escrow company, but when the time comes, they will have you send them to an account outside the US, where you will have no recourse - not to an escrow company.
Once they have your $$$ - you will never hear from them again.