have to put this in perspective. camera/photography is an expense, not an investment, a career for very very few.
in any case, you buy when you decide to buy, regardless the price. it would be nice to find a cheaper one. if you are in financial straitjacket, it is unlikely you will spend more money on cameras. if you are a die-hard fan, you can certainly find few thousand bucks, which is not too much more than, let's say, one mortgage payment/rent.
If you really want to buy low and sell high, you are in the wrong business. Regardless, I think MP can retain more resale value than M7. Your marginal cost will be only few hundred bucks. Better than what you can say about digital ting.