Generally, no. As covered in the Terms of Service (see esp. the Refunds Policy section), all sales are final for all the reasons listed there, and orders can't be canceled or modified once they've been finalized via checkout. This is a small operation with no employees sitting around to do paperwork and run errands. There's just me. Editing orders, adding items, removing items, or changing out items in an order that has already been placed is a logistical and bookkeeping nightmare and a huge time suck, and it invites error into a system that I've worked very hard to make as error-proof as possible.  So please ask any questions you have before checking out.