I know what you mean about cost:
In the last few months, I've spent:
* $700 on 2nd hand coilovers
* $550 on a suspension refresh kit from ECS
* $1,000 on brake rotors/pads
Fitting it all is about to cost me another $1,000. And that doesn't include any upgrades (the coilovers are technically an upgrade, but they're cheaper than stock replacement suspension)!