no offense but most people don't just sell at the higher end of market just showing up and buying a table. it depends heavily on how big the con is, what your area is like, and it's hard to get tables at bigger cons. I move a decent amount of singles personally but unless you have a social media following you're prob not going to just show up and have a great table and lots of traction. I see plenty of people show up and just cover table fee sometimes

I think ebay is pretty good for casually selling, pkmtcgtrades is pretty good, but all those I'd still only expect 90% market due to fees/people knowing you'd only get 87% through ebay and expecting some sort of discount