Are they asking you for any upfront fees? Are they promising to sell your TS for way above market value? How much is the deposit and why do they need one? Legitimate sellers take any profits out of the proceeds of the sale. Those are some signs of a scam.
However, since it was at a presentation and not an unsolicited phone call, it might not be one of those infamous upfront fee scams. OTOH, we've heard here many times how these presentations (especially in Mexico) make you these wild promises of trading up using the value or equity in your current TS to bring down the price of an already over-priced more expensive one.
What usually happens in cases like these is that, if the TS owner agrees to go ahead with the deal, the company fails to sell the first unit but then sells the second unit to the owner with the alleged discount from the original. Now the owner is stuck with two TSs and their accompanying MFs.
