For example, it might make sense for us to have a really nice Maine beach time share because we can either have a "cheap" (i.e. no airfare) vacation OR trade it for something better. 

Airfare and hotel costs are a drop in the bucket in the grand scheme of things.

Hotels are half empty, airfare is cheap and you get good service.

There are several issues at play IMO:1 - Increased Supply - I would not quite say saturation (at least here) but higher supply means more options to guests and lower prices.2 - Lower Demand - General Economic conditions coupled with high airfare cost and airfare hassle etc affecting demand.Luckily for us FL is growing and has a strong historic tourist economy.

Have you checked airfare YoY?

Also when Amex points are used for airfare, they offer the highest value.  

Taking my parents to Hawaii in a couple weeks, round trip airfare for 4, paid for by credit card points.

@Jay Styles If you're considering Colorado, here's some things to note that are in line with what you're looking at:Cheap airfare: Denver is a hub for United and Frontier.

I am a points junkie  so I guess unless I was going to rent some bad pad for a big group I just stick to hotels were I get my points.. same with air fare.. only fly on airlines were I get my points so I get to VIP status and free upgrades... but I fly a lot and I stay in hotels a lot..

Hopefully you deducted that airfare from Tokyo to the US as a business expense!