If your dealer quoted you $150 for a set of SE skirts, that's pretty good. Dealers charge arms and legs for those.
You might want to consider SVT skirts. They're cheaper (oddly enough) -- about $100 a set, but they do look a little out of place without the matching front and sides since they hang a little bit lower than the SEs.
Don't be surprised if it costs more to paint the skirts than that, unless you're having them painted at Maaco.
Never had to have it done myself, and I've never seen a quote on skirt painting, but the price to paint a front bumper is in the neighborhood of $300-$500 at a good shop.
Installation should be really easy since the holes are already there. I wouldn't be surprised if it's less than $100.
