Special assigment
Of course I let Bishop spend the money on the spy-stuff he wanted. Spy stuff could only be good for me, and what else I could spend the gold on? That wasn't a rhetorical question, because simply investing money took too much time and brought too little result. No. If I was going to make money, then I would have to use faster means.
"Bishop, if you will be low on money next time I appear… or if you will need more for a project… Do this—take the rainbow stone and sell the water from it to adventurers. But not fresh, let it wait for ten-fifteen hours. Its effects are especially noticeable the first time you drink it and diminish later, so after the first try people will instantly get impressed, after which you will be able to raise prices sky-high and cut the stock to create a shortage. Of course, your cult members will still get the freshest stuff and as much as they can stomach."