Buy! Buy! Buy! and Sell! Sell! Sell! adjusts the amount of gold the user spends on Life Savings and Precious Gem. The more gold the user spends, the more healing/slow & damage comes from those abilities. It gives the user some flexibility. For Example, if an allied hero is very low on health, I would use Buy! Buy! Buy! a few times to increase the healing of Life Savings and output massive burst heals. If an allied hero just needs his health bar topped off, I would use Sell! Sell! Sell!...

Forgot to explain this, yes the Q has global range except when targeting enemies.