Hmm. Well "gold" should be just the symbol true, not the string "True".

Could it be that your bids.json is not an array? Happy to help debug it if it's something else too.

bids.json

[
{ "card_detail_id": 439, "amount": 2, "bid_usd": "6.00", "edition": 7, "gold": True }
]

Edit: code