From what it sounds like, you want to pay with bitcoin on Credit, meaning you get the bitcoin then pay within say 30 days. This would be terribly risky for the seller as if you were to no pay then they could not take your bitcoin back. Even if escrow was used you could simply not pay if the price went against you, and you would pay if the price went up.
Thanks for this thought,
It was for the reason described above, but now I have a new angle, thx
You are welcome. I would find it very much unlikely that it will not be able to pay for bitcoin via invoice unless you are able to get a legally binding contract signed prior to sending the bitcoin and are able to document sufficient income and assets that can repay the funds borrowed.