Ya know it's sad. I saw this post with absolutely no responses to it (in almost a months time) and thought to myself how much some people are really missing the boat.
PSP is a very adequate, capable, and competitive piece of software. It's much more intuitive and user friendly than PS, or even PSE, IMO. And can be found for half the price than PSE if one looks around well enough (I paid $49.99 for PSP X1, on sale @ BestBuy, about 6 months or so ago). For someone new to image editing software, it's a great starter program. The only fault I found with it is that it didn't recognise the PEF RAW files, but the new release of X2 does, and it also has the new Express Lab which has a built in HDR function.
Plugins and Add-ons? A lot of those made for PS/PSE will also work in PSP.
Is it just that everyone thinks that PS/PSE is the "gold standard"? That unless it has that Adobe brand on the box it's no good? (While Adobe laughs all the way to the bank)
I guess if one is really ... really ... REALLY a pro, and can justify, write off, or has someone else paying for it, then I could see the outlay of expense for PS. But for most of us, less is more. You could be buying gear for all that cash!!