Like everything else in our cars, the carpet is getting more and more complex. 3-dimensional shapes, attached special padding and contouring panels on the bottom, etc. These details are the kind of thing aftermarket doesn't do well, in my experience. It likely won't be very cheap, and likely won't fit correctly.
So, for OEM, the carpet panel from the rear wheel wells forward retails for about $1300, and the rear part is about $600. Discount sites knock that down to about $900 and $400 respectively.
Also consider to replace the front portion you will need to remove the center console with the coolbox.. this is a very involved job, potentially involving evacuation & refill of the AC system from what I've seen on here.