Custom water cooling

I am fairly new to the PC world and was wondering what sort of costs I would be looking at to set up custom water cooling. 

What do you want to cool ?

cpu, gpu, possibly ram

well for a CPU only loop your looking at about 250-300 and for CPU+GPU about 400-500

You can get as low as like 350, and go as high as you really want. With just a cpu, gpu loop you could spend 600 dollars on an amazing loop. Cooling ram has no real benifits. The small OC you might get out of it isnt worth the cost of the block.

Ok, thanks. I'm mostly wondering because I'm gonna upgrade my case and wanted to see if it would be worth getting one That supports it. I might just go with an h100i or nzxt kraken x60 or something 

Custom loops are higher maintaince, but also if built properly have much better performance. If you want an easy solution a premade loop might be your best bet.