What's the old saying? "If you have to ask..."
I wouldn't put much money into any boat if you seriously fear the consequences of having the resale market dip badly. The boat market is capable of dipping about as low as anything on Earth. It's dipped a lot, but can go plenty further.
With a used boat, the best assurance you'd have of not losing your shirt on resale is getting a very good price relative to today's market, so long as you KNOW the hull and drivetrain are sound. Within the confines of respected makers, this is far more important than the specific model of the boat. If you buy anything as big as a 30 especially, I'd pay for a survey and make ALL money, including deposit, ENTIRELY contingent upon survey.
Aside from that, twins are expensive. And gas for twins is expensive. And anything as big as a 30 is certainly a lot more expensive than something down near 20. To a point, when the economy dips, you can actually see a shift where twin engine boats are de-valued and singles sometimes become more valuable (or at least more valuable RELATIVE to twins.)
If you're this worried about resale, I'd be inclined to focus more on single engine boats, unless you're absolutely certain the boat is well sorted and you're getting a STEAL of a deal.
"I don't have time to get into it, but he went through a lot." -Pulp Fiction