Why not buy from an unsigned account?

I want to buy bitcoin. I am already “signed”. What is the danger or logic of why not to buy from an “unsigned” account that sometimes has a juicy-too-good-to-be-true offer such as 3% below market value and a high value?

I would not worry about buying from an unsigned account. Signings is more about giving seller’s extra confidence about buyers.

Less risk when buying bitcoin then selling as you do not need to worry about chargeback risk.