Emissions has caused the cost of I/O's to rise dramatically. That's why your seeing a resurgence of OB's in entry level family runabouts. The market is really changing on top of that. A few years ago the #1 selling fiberglass boat in the land of 10,000 lakes(MN) was Malibu! Think about that for a second. Volvo doesn't even offer the 3.0 4 banger anymore. I'll also say where I live changes in the market has kept the resale value of used sterndrive boats stronger than ever.
Personally I'll buy a boat with sails before I ever own another OB or get out of boating altogether. Prefer the looks, sound and feel of a sterndrive over an OB. "Give me sterndrive or give me death!"