'Buy' in the Bible

I counsel thee to buy of me gold tried in the fire, that thou mayest be rich; and white raiment, that thou mayest be clothed, and that the shame of thy nakedness do not appear; and anoint thine eyes with eyesalve, that thou mayest see.

And that no man might buy or sell, save he that had the mark, or the name of the beast, or the number of his name.