Transaction Underpriced in BSC network

No matter what I try to do, always in a purchase attempt using web3 I get ( {'code': -32000, 'message': 'replacement transaction underpriced'} ). I've tried everything, increase gas, change values, pay more but nothing works... could someone smart save me?

def buy(token_id, price):
tx = bid(token_id, int(price * 1000000000000000000)).buildTransaction({
        'chainId': 56,
        'from': MY_WALLET_ADRESS,
        'nonce': w3.eth.getTransactionCount(MY_WALLET_ADRESS),
        'gas': 400000,
        'gasPrice': Web3.toWei(25, 'gwei')
    })

signed_txn = w3.eth.account.sign_transaction(tx, private_key=MY_PK)
tx = w3.eth.send_raw_transaction(signed_txn.rawTransaction)
pending_tx.append(tx)

Here's a part of where I'm having difficulties.