I have a 2007 premium package g35 coupe. I was wondering the cost to swap out the current suspension to a oem sport tuned suspension? Is it worth it? Can you buy them from people here? Is it hard to install?

Probably better off just going aftermarket.

seriously just get aftermarket

Install isn't too bad. If you work on the car often, it's just another project. There are DIYs on here that will help guide you. Just take your time, double check everything, and make sure everything is torqued to spec. When it comes to suspension, if things aren't torqued down correctly you can have creaks and other noises occur.

As far as parts, just go aftermarket. Tokico blues are a good choice if you are on stock springs. Some Koni Yellows or Tokico D specs are good if you're on aftermarket springs or are looking for more performance capabilities. Those will allow you to adjust the dampening to suit your driving style/needs.

Not worth it, just go aftermarket like others have said.

what are your overall height and stance goals?? thatll prolly help you decide whats best for you. but regardless im on the aftermarket boat as well