TI3 is a great game, but it's sooo expensive, especially with the expansions. Also takes a lot of time and you need a pretty dedicated group. That said, it's probably my favorite board game even with the ridiculous complexity.
Yeah, the expense would probably be my main issue - $90 for the main game and $60 or so for each expansion? FF does nice gaming stuff, but that's a tad pricey for me. I did lol at one of the comments I saw on Board Game Geek, that the huge TI3 main box is great for fishing tackle.
Cosmic Encounter is similar in some respects, and less expensive for the main game and the three expansions. There are nearly a hundred races to choose from, and each race has its own unique ability. There's also a color code to represent how advanced the abilities are, so that newer players won't get stuck trying to use a more complicated ability that requires familiarity with the engine to be effective.