Vintage T-Shirt Forum & Community Authentication Appraisals

Hi,
glad to have found this space for comparison, I find myself needing to sell a set of collectible t-shirts for a move, while I have identified the "authors" to whom they relate, I cannot define a valid quotation to try to sell them, maybe someone in this forum could help?

Thanks in advance!

BAND: MGZ (IT)
YEAR:
MATERIAL:

These are very obscure t-shirts, and tough to appraise, but I reckon they have niche value in Italy and other euro countries. I can't find any trace of them anywhere else, including eBay's past sales. Where do you plan on selling?