Could you please enlighten me on the cost of executing a Bitcoin transaction involving a sum of $1000? I'm particularly interested in understanding the transaction fee associated with this amount. Is there a standard fee that applies regardless of the exchange platform or wallet service? Also, does the fee vary depending on factors such as network congestion or transaction priority? It would be helpful if you could provide an estimate or a range of possible fees for such a transaction. Thank you for your assistance in clarifying this matter.