I got a regulator for 20-30$ off ebay, needel valves can be had for 15-35$ depending on what you want to use/pay, same with the regulators, I like Victor Reg;s they are 110$ or so new here. But they are the best around.
Gas tanks run 40-70$ for 10-20lbs at fire extingusher places, Ice and micro brew supply places, reactors can be done DIY for a few$$.

But you can certainly do things cheaper if you look around and local to your local plants club if there are any locally.

Regards,
Tom Barr