We started from a roughly similar situation. We started looking casually at DVC years ago, too... and dismissed it because it was a timeshare. We continued to go to WDW almost once a year (with a two year hiatus because of the birth of DS. We always stayed at Deluxe resorts Concierge level (in our case, BC, BW, or GF) and we almost always got either two rooms or a suite because DM enjoyed travelling with us. We looked at DVC very seriously in 2006, and decided we would probably buy in some day (once we'd finished expanding our family - we knew we'd either be doing IVF or adopting and either route was going to use a substantial amount of money.) Even after we knew we wanted to buy in, we took two pretty elaborate vacations. We were planning a third when we realized we were being "penny wise and pound foolish", as my grandfather used to say. Planning to buy in "some day" and continuing to spend thousands and thousands of dollars on hotel rooms just didn't make sense.
Instead of a fall trip last year, we put our trip off to January and bought DVC. We bought one contract from Disney and one resale. I would do either again, depending on the deals and incentives currently offered. Buying from Disney was much faster and easier and we have already enjoyed using up our developer points. Considering that we would have spent at least $3000 on the amount of space for the amount of time we got for using the developer points, I don't think it was a bad deal at all. (We saved ~$2000 on the contract we bought resale, and it was fully loaded with banked points, so we didn't feel like that was a bad deal, either. It was just a headache dealing with it.)
We will echo the sentiment that we wish we had bought in earlier. We had the money to do so, we just weren't convinced it was the right time for us. We now think we were wrong
I know there are a lot of people who are unhappy with the direction DVC has gone in the last couple of years, but it makes a lot of sense for some people, including us.
We did buy where we wanted, or at least were willing, to stay all the time. We had heard that advice enough that we knew we wanted to follow it.
We did not buy with the intent of trading out often, if ever. We like to cruise, so we plan to continue to take cruises. We like Hawaii, but not the long flight with a little kid, so we've put Hawaii on hiatus, anyway. (If DVC ever does finish the Hawaii property, we'll be buying enough points for a two bedroom ocean view villa for a week+ once every three years.) We have access to an adequate, if not fabulous, beach nearby, anyway, so beaches aren't a huge deal to us. We'll probably try Vero Beach at some point, just for a change, but it won't be any time soon. We bought our points to stay at WDW, and that is almost certainly what we'll use them for.
I don't know about how much luck you'll have scheduling "last minute" trips. We sort of looked into it last fall, and we couldn't find enough consecutive nights to make it worth our while. (We're not into switching rooms nightly... no more than one room change per trip for us.)