maybe we can make some sort of mall with different shops
like:
some sort of home depot wich sells decoration items like coloured glass, carpets, dye's etc.
a supermarket wich sells food and food preparations like seeds.
a music shop wich sells music discs.
a armoury wich sells enchanted armour and weapons.
a pharmacy wich sells potions.
a hardware store wich sells redstone related items.
some sort of quarryman wich sells stones like prismarines, netherbrick but stone bricks aswell.
etc.
though these shops do kinda ruin the meaning of survival you can leave some shops out
and we do need to take the player markets in account because if we have the shops at a low price, the player markets will be useless.
we could also make a better market with bigger shops so players can sell or without having to purchase multiple market stalls
so more players can have a wide variety of items and blocks to sell
instead of being limited to a small space and trying to make the shop look inviting without taking to much space away for chests.
There are some of those I could get behind, redstone stuff for instance, which are used for the insular part of the game detailed construction etc. Potions, enchantments, more external items, should definitely be for sale on the player market with a server buy chest to maintain a minimum price.
However a complex player market isn't going to generate spontaneously, admin may have to make some player stalls of what they'd like to see people buying and selling, just to wet peoples beaks.