Gold pricing and gold per gram.

Just need a quick bit of help. I’ve been sorting out all my costs and advertising for my business to open beginning 2021. I have a few close contacts for diamonds and polishing but biggest thing I’m struggling to find is a caster because of how they price and understanding the cost. I have my own 3D printer and also wax grills my self. But a few companies are charging 26/28 pound per gram 9ct gold and 14ct at around 42 ish per gram. But some companies are charging like 2 pound per gram. Please send me suggestions and help me out on this little problem please so I can get the cost sheets finished and get the best casters in London. 👍👍

Nobody is going to charge £2/g for gold (well, not for long anyway - the loss would bankrupt them quickly). It might be how much the charge is per gram over the base cost of the gold, but it's not going to be an absolute cost.
If you've got a question about a caster's pricing structure, then the people to answer it are the casters themselves.

I'd suggest testing to see how well they can cast your prints before committing though - there's still a number of casters can't seem to handle 3d prints with any reasonable quality. Part of that is down to the variations in requirements for burnout, especially with resins.