This is an example product and description.

I would recommend using lightboxes so that people can view bigger pictures and the description on the merch page, and then put a hyperlink in the description  to open another site (e.g. Etsy) where the product can be purchased. Also use this as the "Source URL".

Pop the price under description and make sure the image description is visible in the gallery on the "Merch" page.

Use this invisible/not-linked gallery page to add new merch, similar to how you will add new events, and it will display on the merch page.

This info can be kept as a "Draft" and it wont be visible on the Merch page

Example description