There are a whole bunch of skin packs missing from your market place. for example festive skin pack (not the mashup pack!) it had a santa creeper in 2013 that I bought and couldn't find in bedrock edition. I know there are a whole bunch more. You can check the minecraft wiki and or mojang4js logs on skin packs. I would like all of them ported over to bedrock including the discontinued ones like sim or marvel. 

List of all known skin packs from legacy editions - console edition
https://minecraft.fandom.com/wiki/Skin_pack