Which give the best bang for your Bibbidi-Bobbidi buck
If you Connive enough with the legendary creature and discard nonlands to pump its power, then its second ability becomes more powerful by granting Double Strike to stronger and stronger creatures
(Oriental Light and Magic), on Kubo's suggestion
If you are sending individual cards worth $50 or more, make sure the insurance will cover this This might sound stupid but...don't use the money you got from the cards until you are sure they have arrived safely, the last thing you want is to have to refund $300 to someone while you wait for insurance (or not) but you are unable to as you already bought something else with it
Using a Toploader makes this less of an issue
(2021-09-24) To determine the total cost of a spell, start with the mana cost or alternative cost (such as a flashback cost) you're paying, add any cost increases, then apply any cost reductions