If you can afford it now and it's the kit you want get it NOW! It can always wait until you're ready to install. If you wait the deal and kit may not be around when you're ready for it.
Current 2012 stock Focus
SOLD 2006 ZX3 SAP, Draxas Header, MBRP exhaust, CAI, Tuned, Debaged, FRPP lowering kit, SVT 5spoke wheels, Black Halo Projector Headlights, Niteshaded Side markers/tails, Mazda rear wiper, mustang antenna