'Buy' in the Bible

Therefore I counsel you to buy of Me gold refined in the fire that you may become rich, and white robes to put on, so as to hide your shameful nakedness, and eye-salve to anoint your eyes with, so that you may be able to see.

in order that no one should be allowed to buy or sell unless he had the mark--either the name of the Wild Beast or the number which his name represents.