I'm in the same boat right now for project templates of my engine. I'm just using reiners and crappy custom work right now as placeholders.
There are plenty of good sprite artists out there, you just need to find and steal them from the freebie/newbie gamemaker & alike projects.
Frequently i'll just purchase 3d model packs and set up my own renders and animations of the models into 2d sprite/tile sheets, just as Mortiis suggested, although it doesn't look half as good as well done sprite work, and usually just destroys the style.
I have seen some really impressive 2d sprites here on the blitz forum in the showcase, but I think they keep their secrets to themselves =P
I was quoted around 2k for some pacman spites a couple of years ago.
I think I would tell him/her where my foot is going to go if I ever ran into them in person.