it sounds kinda pricey , you should find a better deal than that, for 20 grand you might find an 05 sti , i'd definitely consider the 05 sti over 04 here's why
2005 Subaru Impreza WRX and STi spec page


new Helical Front limited slip differential
new power steering oil cooler
new wider 8" wheel (replaces 7.5")
new rear wheel arch flares, body colored (because the new 8" whl?)
new Immobilizer key, 3 supplied. Needed to start car
new Yaw sensor (part of the lateral G sensor)
new climate control
new air filtration
new smoked headlight lens
new daytime running lights
new re-designed keyless remote fob
new seat cushion side bolster material
new center console cupholders, replaces the one by the center vent
new sam/fm/CD changer w/ bass, mid, treble adjustments, 6 spkrs
new door armrest redesigned, now cloth, includes mirror controls
new colors

keep searching and you'll find a better deal for an instance eBay Motors: Subaru : Impreza (item 250207300504 end time Jan-24-08 15:01:08 PST)

the other "cem" from floridasubarus bought this 05 sti last year with 14k miles on it for just 23k..
good luck