Nooo, never ever waste gold on training oratory unless you absolutely are against being a diplomat.
It doesn't matter your main class, as long as you are a diplomat, you do not need to spend any gold on getting your Oratory skill above 80%. You just need either a region you like, or a ton of treaties, and some patience.
Oh yeah, did I mention patience? A few years ago, more than two players one separate occasions told me that BM is a game of patience. And possibly repetition.
You want to be the best? Deal with the boring early stages. It gets easier, faster, and better after the first few hurdles. Really.
I had a character start as inexperienced, 5% oratory. At this point, she has all priest options, all diplomatic options. With the best result in praising for 4 hours, she at one point raised 5 loyalty. This all occurred recently after only about two months.
Sure, or you could spend about 50 gold and shave a month or two off the process. The fact is training at the academy early gives you rapid skill gain, that gets you to the point were further skill gain from actually preforming your task is a much better prospect. That first 5-10% seems to be damn slow to happen out in the field.
