The key to establishing productive no till beds is adding a lot of organic material over the cardboard/newspaper/existing grass, and being patient.

They won't produce well the first year unless you add a lot of topsoil and compost right away (like 8-12 inches).

Most beds won't hit their stride for a few seasons. They often need topping up with more material in years two and three, as the underlying stuff breaks down. I like to start new beds in the fall so they're more established by spring.

All of this is to say, no need to undo your hard work so far. Just add more stuff on top (and maybe sow a cover crop in the fall to keep the soil biology alive.) Good luck!

If that isn't panning out, you could reach out to local landscapers who specialize in native plant design and offer them a good deal, especially toward the end of the season. They may have jobs spec'd that they still need to fill, or be willing to design around what you have. In any case, I hope you can find good homes for them!

Have you kept track of the species and approximate quantities of each? A solid spreadsheet or inventory list that you can circulate to nearby groups or organizations would probably drum up more interest than random pop-ups or sales.