I couldn't really find any datapacks that people have made to add more items to the Market, so I decided to give it a go myself.

This datapack contains most, or all, of the soil, fertilizer, flowers, saplings, seeds, berries, and mushrooms from the following mods:

• BetterEnd Reforged
• BetterNether Reforged
• Buzzier Bees
• Cinderscapes
• Create
• Endergetic Expansion
• Farmer's Delight
• Minecolonies
• Minecraft Earth Mod
• Nether's Delight
• Outer End
• Quark
• Supplementaries
• The Abyss 2
• Tropicraft
• Twilight Forest

Edit:
Here is an updated version of the datapack where everything is separated by mod and type, allowing you to easily disable the mods and items you might not want.

farmingforblockheads_shopexpansion.zip

Thanks for the submission, I've added it in 1.17+ (but changed a few to be disabled by default)