Hi,
I feel the best way to ship a single card is this:
- Put the card in a sleeve
- Put the sleeved card in a topload
- Put the topload in a "team bag"
- Put another topload on each side of the original topload
- Seal the bag and put a piece of tape along the seal
- Put the whole works in a small bubble mailer
Works well for me. BTW the seller should reimburse the OP for the cost of the card plus shipping.