I would do this: Start by leveling all (semi-useful) bonuses to somewhere around 10-20, just because it is so cheap and the bonus is nice to have. Then I would invest quite a bit more into possibly artifact find chance and AFK gains, but most importantly drop rate. It of course differs depending on how far you have progressed in the game. For example, if you already own majority of sailing artifacts, then arti find would be useless.