Not necessarily so!
I agree that good lighting will will be one of, if not the biggest expense, but there is no need to spend nearly that much money on lights!
While thegrun is right that leds will be less expensive in the long run, they don't need to even cost as much as the t5 fixture you are looking at for $900.
At the lowest end, a set of 2 or 3 MarsAqua fixtures will cost $200 or $300 total and provide more than enough light for an all sps reef!
You want more features in your fixture? Name the ones you want. Sunrise/sunset, moonlights, more than 2 channel color control, multiple modes of lighting, more shimmer? You can have all of those features in a very thin and modern looking Reef Breeders Photon V2 in either a 32" or 48" length for under $590. And there is a list of other led suppliers that offer different assortments of these features for less than $500. See this post:
http://www.reefcentral.com/forums/showpost.php?p=25052764&postcount=233
You don't need $800 Eco Tech Radions (and you'd need 2), to have a great light on your tank. The Radion is like the Mercedes Benz of led fixtures. Yes, it's a very good fixture. But IMHO, it's over priced. The Photon V2 48" for $590 will do 95% of what 2 Radions (%1600 total) can do in terms of features, it still looks great (even better to my eye) and it still produces light every bit as good as a Radion.
But don't take my word for it. Look at the features available, decide which ones you want and what your willing to budget. Then get what suits your needs, do let anybody tell you the fixture they have is the 'best' or the 'one you should get'. Not even me! Get the one that fits your needs best. They all make light that will look good and grow coral, even the MarsAqua for $100/fixture.