If you have been kyced and you have successfully migrated to mainnet wallet.
You can actually trade your pi coins to cash and other crypto investments.
The only once you can actually migrate are your transferable balance.
That said, if you are looking to trade your pi coins to a pi vendor, then I'll leave you with the contact of my personal trusted pi vendor you can contact him to trade your pi coin.
Telegram: Pitradeboard
WhatsApp: +2347081566992