The difference with buying a DSLR versus a point shoot is that you aren't buying just a "camera". You are actually buying into a "system". So now that you have the base "system" you can now expand that system to do more and other things. Each lens you buy can expand your system.
Think of like buying a mac or apple computer. You are buying into a system. You get the base components that will allow you later on to get the airport, timecapsule, etc.
The difference being is that the camera itself doesn't really do much, it is the lens that dictates what the camera can do. Thus more energy (and thus $$) goes into the lens. And because it is a niche market the smaller the market for the lens' capabilities, the larger the price. The more you want the lens to do, the bigger the price tag.
The lens I am looking has a pricetag of about $1000 CDN. So it is something I have to seriously be sure about. And lately I've been reading some negative things about it, making me second guess it. But I haven't found anything that is comparable for what I want it do yet.
The one issue I have had with the Pentax line is that lenses aren't that readily available to me here in northern BC. I practically have to order everything I want for it (Speedlight, grip and lenses). There is something to be said about being able to see the lens on the camera feel its heft. So it just means I have to do that much more research.
(and do Holly and Marilyn know about it)
to all who aren't feeling well 
