One need only reference old MacUser or MacWorld magazines during that period to determine price and price stability from debut to EOL. I have those magazines at my parent's home in California, but unfortunately, I do not have access to them now that I am in Japan. Therefore, one of you who also retain such old magazines will need to look.

But what I can say for now is that the SE/30 WIKI and EveryMac cite an introductory price of $6,500:

http://en.wikipedia.org/wiki/Macintosh_SE/30

http://www.everymac.com/systems/apple/mac_classic/stats/mac_se30.html

The Old-Computers.com museum cites the $4,400 price mentioned by luddite above:

http://www.old-computers.com/museum/computer.asp?c=162

This article gives pricing by model (hard drive size and RAM):

http://www.vectronicsappleworld.com/macintosh/se30.php