I want to tell the buyer that these comics are being offered are currently being shipped to me from BTGC and I will ship as soon as they arrive.

Here’s a clean, seller-friendly version you can drop right into your eBay or Whatnot description or message:

> These comics are currently in transit from BTGC. I’ll ship your order as soon as they arrive—usually within a few days of delivery to me. Thanks for your patience and for supporting independent sellers!

If you want a slightly more formal listing-note style:

> **Note:** These comics are presently being shipped to me from BTGC. Your order will be mailed immediately upon arrival. Estimated handling time may vary slightly depending on carrier delivery.

Would you like it rewritten for eBay, Whatnot, or both (tone and length differ)?