He can say with certainty that If the Blood Skull sect has money but doesn't have the beast carcasses to buy, or if the beast carcasses are available but they don't have the money to buy them, a nascent soul senior being killed by a golden core junior will be the least of everyone's worries.
Arthur chuckled to himself when he thought about this. He said to himself, "I guess this is what it means to be at the top of the world."
With such a condition, he truly can't complain that forging the divine armament is too difficult. It will be foolish of him to do so.
He could only get a textbook and begin drawing schematics and working out the formulas to make sense of them.
At least, his mind is more powerful than when he was a mortal. He can learn better and faster now. So the difficulty lies primarily in the process being tedious. As long as he works hard and doesn't give up, he will eventually learn it.