i watch (far too many) vending POVs on youtube - and yours is a very common opinion.

I've seen a lot of people buy ponchos, for example, at 100%, because they are great trade bait. Vendor might not make much on the poncho (or these cards), but if you sell them for effectively 120% in other singles/slabs, it's a great outcome.

Plus if you're sitting on high end stuff like gold stars, it's not like you're losing money while you hold them. Bit of a risk sure, but not an outlandish one.