Hmm. SE3 and SE2 are still fun games in their own right. In fact I'd say SE3 is more fun than SE4 in spite of its lack of features.
$30 isn't a lot of money, even for a really poor game. The compilation CD is a great deal because it has both those games plus SE1 and a whole bunch of mods and shipsets for SE3.
Odds are if you own a computer you can afford a $30 CD. If you don't care it doesn't matter, but if you really want those older games $30 is not an obstacle.