★ New cards added every week · Collector-owned marketplace

We'd Love To Hear From You

Contact Us

Whether you have a question about an order, are searching for a specific card, or are interested in selling a collection, we're here to help.

Customer Support

Questions about an order, shipping, returns, or your account? We're happy to help.

Looking for a Card?

Searching for a specific player, rookie, parallel, autograph, or graded card? Let us know and we'll keep an eye out.

Selling a Collection

Have a sports card collection to sell? Contact us with the details and we'll discuss purchasing opportunities.

Contact Information

Email:

eric@sidelinementality.com

We typically respond within one business day.

Please include your order number if your question is related to an existing purchase.

Before You Contact Us

  • Include your name.
  • Include your order number (if applicable).
  • Describe the issue or question clearly.
  • Attach photos if you're reporting shipping damage.

Need Something Specific?

Looking for a particular card?

We're constantly adding inventory. If you don't see the card you're looking for, send us a message. We may already have one coming into inventory or can help locate it.

Last updated: July 23, 2026