Beer brewing supplies are in general things that you have to buy new for every batch.
Compared to the list in the beer brewing equipment these are returning expenses that you have to calculate in the cost of your batch
The first thing I suggest you do is to read my take on how to start home beer brewing.
A beer kit is in many ways the best way to get started until you have some more experience and can start from scratch. I have a whole page filled with ideas and links to the best home beer-making kits.
You can argue that this is a piece of equipment and I leave that up to you to decide. I use them over and over again so I think it is a supply. At the moment of me writing this, all I use are Grolsch Bottles. There are, however, many other options that I will write about later.
The use of the right bottle caps is many times overlooked. The result can be a ruined batch of beer. There are here also many options to choose from and that is why I have dedicated a whole page to homebrew bottle caps.
You also need a good bottle-capping tool for the best result.
As a passionate home brewer of beer and wine and an amateur connoisseur. Eddie McVay has a fast experience in the subject and shares all his tips here on this website. You can read more on this page about Eddie McVay