The website for a local video game shop has Disgaea listed at $24.99 new. It also has the Final Fantasy Anthology Strategy Guide listed at $14.99. The last time I tried to put an order through, the website had trouble accepting credit cards. However, I was able to put a call through and pick up a sealed Disgaea, as well as a copy of Valkyrie Profile for $35 (unfortunately this was the last copy). However, YMMV. I can't vouch for the website, but the local stores are great and carry an excellent selection of classic games. The link is:
http://www.slackerscdsandgames.com/
Good luck!
http://www.slackerscdsandgames.com/
Good luck!