The K-1 and K-1II are as good now as they were upon release
They're an
especially good option now since, new or used, the pricing is very affordable for such high image and build quality. You could wait for a new model to be released, but it will be considerably more expensive and you'll lose all that shooting time. If you buy a K-1 or K-1II now, there's no reason why you can't sell it or part-exchange it when a new model is released. Consider any small financial loss to be "rental" for the time you own it