Made a mid sized sale last night around 11pm. Sent buyer a thanks message and told them it would ship monday morning. My ship window is 2 days so no issue I thought . Buyer sent me a message asking about other sets, is interested in purchasing. Can I hold onto the original set at their request to combine the shipment, even if it takes me over my 2 days? Will I get a defect if I do this? Or should I ship the first and deal with any other purchases separately? Buyer is paying for shipping.

eBay doesn't penalize you for metrics like Amazon. As long as there is communication via eBay messaging with the buyer, you're fine to wait an extra day or two to work out the combined sale.

Ok, has hoping for that. Thanks!