?

I have a deep freezer in my garage. It is just a bit smaller than 2 side by side home refrigerators. I think it has a 1/2 HP compressor and it runs on r-22. I know a little about refrigeration and I know how to braze copper. I talked to a tech about the problem I was having and he told me that my TXV (expansion valve) was clogged or bad. He told me if it is bad that I could remove and replace it with a capillary tube for 1/4 the price. The tech I met in the parking lot was in a hurry to go so our conversation pretty much ended there. Last thing he told me was to go buy a capillary tube and ask the clerk about it. Before I do this I would like to know if this is true, is it really 1/4 the price and the basics on how it is done if true just in case the clerk doesn't know.