Ebay:
http://cgi.ebay.com/Space-Empires-IV...QQcmdZViewItem
On the other hand, I've been playing SEIV for around 5 years now. Lets think about that for a moment...
SEIV outlasted dozens, DOZENS of games on my hard disk. heck, it outlasted 3 PC's, an Xbox, a gamecube (and dozens of THOSE games too). Not to mention a few dozen books (Scifi, history, social studies) movies, TV shows, DVD's and blah, blah, blah.
Of all the money I have ever spent entertaining myself in the last 5 years, nothing even can hold a candle to the absolute value of SEIV for 49.95. How many games are on your hard disk now, that came out 5 years ago? If this is the type of game you like, I daresay the $50 will fade into meaningless for you real quick.
j/m .02