There was a DA L 50-200 for sale in the Marketplace, and I was lucky enough to land it, even though I saw it kind of late! *HappyDance* Thank you guys SO MUCH for all your help! If the board lets me, I'm going to give you all rep points.
At first, I was kind of bummed that I couldn't buy something regarded to be better and, out of frustration, even considered selling all my gear and reverting (regressing?) back to an advanced P&S, but I had to have a "talk" with myself about being ungrateful about having gear that other people would LOVE to have, and would trade places with me in a heartbeat to get. So, I had an attitude adjustment session.
When I sat myself down and thought about it, I had to admit that I've never been disappointed by the quality of my kit lens. I've taken some bad shots because of poor composition, or not having the right settings (I try not to shoot in automatic mode), or for some other reason - but it's never been my 18-55 lens' fault. And, when I get it right, my kit is awesome IMHO. If I get at least the same quality results with the 50-200 as I got with my 18-55 I'll be more than content for where I am in my skills development.
So now, I'm going to have an SMC Pentax DA 18-55mm f3.5-5.6 AL II; SMC Pentax DA L 50-200mm f4-5.6 ED; SMC Pentax-M 50mm f1.7; and an SMC Pentax-M 50mm f2 as a backup. ('An' is correct here because the 'S' in SMC sounds like it starts with the vowel 'E'. Right?
) I have two Takumar Bayonets that I'm going to sacrifice towards the worthy cause of a decent macro lens and then I'll have all my bases covered.
Thanks again, everyone!