({3} magic symbol) ({R} magic symbol) ({G} magic symbol) plus enough mana to pay for commander tax, if applicable available.
Steps
Cast Roxanne either from your hand or from the command zone by paying ({3} magic symbol) ({R} magic symbol) ({G} magic symbol) plus commander tax, if applicable.
When Roxanne enters the battlefield, its first ability triggers twice.
Resolve the first trigger, creating a Meteorite artifact token.
When the Meteorite enters the battlefield, it and Amulet of Vigor trigger twice.
Resolve both Meteorite triggers, dealing 4 damage to any target.
Resolve the first Amulet of Vigor trigger, untapping the Meteorite.
Activate the Meteorite by tapping it, adding ({RG} magic symbol) .
Roxanne's second ability triggers, adding ({RG} magic symbol) .
Repeat from step 6 for the remaining Amulet of Vigor trigger.
Repeat from step 3 for the remaining Roxanne trigger.
Activate Temur Sabertooth by paying ({1} magic symbol) ({G} magic symbol) , returning Roxanne from the battlefield to your hand.
Repeat.
Once you have infinite mana, you may forego tapping the Meteorites for mana and/or add mana of any color(s).