'Buy' in the Bible

I advise you to buy from me gold refined by fire, in order that you may become rich, and white clothing, in order that you may be clothed and the shame of your nakedness may not be revealed, and eye salve to smear on your eyes, in order that you may see.

and that no one was able to buy or to sell except the one who had the mark--the name of the beast or the number of his name.