how much is the CO2 tube

There is a CO2 marking machine , the CO2 tube needs to replace. Who know the manufacturer of it and how about the price?

1: power 30W,length 80cm

2: power 60w, length 120cm

and the price of Nd: YAG rod ,the size as following:diameter 6mm, length more than 110mm.

and the Xe lamp: diameter 7mm, length 210mm, the distance between pole 100mm.

这些东西满大街都是，厂家售，代理售，等等...

As for CO2 tube ,I have not used it even before ,so I'm not familiar with it.Whether there is some difference between them? I mean I do not know each of them can be used in our marking machine. The coupler in the end of tube is the same with each other? Thanks very much.

I know there are a lot of manufacturer , hehe, I just want to campare the prices, of course , I want to buy the cheaper product with good quality.