Both are normal here. Metzee is not makers-only, and a reseller is not a second-class seller. Who can sell on Metzee
They are genuinely different businesses, though, and the differences are worth knowing before you pick.
What a maker has
A story that is true, and it sells. People buy from makers partly because of the making.
Control of supply. You can make more of what sells.
Better margins, usually, because you are not buying stock.
No authenticity question. You made it.
What a maker struggles with
Volume. You can only make so much, and a good show can clear a month's work in an hour.
Pricing your own time, which almost every maker does too low.
Every piece differing, which is an advantage live and a description problem elsewhere. How to write a condition description
What a reseller has
Volume, immediately. You can buy a hundred items this week.
Range. You can follow what sells rather than what you can make.
Speed. No production time between deciding and listing.
What a reseller struggles with
Knowing less about the item than a maker does. You did not make it, so measure it, weigh it, photograph the flaws, and say what you do not know. "Unmarked, I cannot confirm the maker" is stronger than a confident guess that becomes a return. Five questions worth asking before you bid
Buying price discipline. Buy at a price that survives a disappointing sale, not a hopeful one. Where do sellers find stock?
Authenticity, in the frequently-faked categories. How to spot a counterfeit before you bid
The one rule that applies to both
Do not imply you made something you did not. It is the fastest way to lose a buyer who finds out, and buyers of specific things do find out.
If you resell, say so. "I find these and bring them to you" is a proposition some buyers prefer, because your range is wider than a maker's.
Doing both
Common, and it works — your own work plus pieces you have sourced. Keep the descriptions clear about which is which, and it is simply a wider store.
What does not differ
Fees, delivery, returns, standards, the 7-day window on anything faulty. The app does not know or care which you are. What it costs to sell
More: can I buy things to resell, what sells well in a live auction, where do sellers find stock.