I have noticed, while playing on my balance alt, that some of the shopkeepers in the regent square shops have been charging more than they ask for.
I tried to buy the orange-brown version, which cost something around 2660, and I had about 3000 coins. Then when I clicked buy it said transaction was not successful, so I tried out brown-brown, which cost about 1000 coins and it worked for that. Then I went to a different store, and had about 2000 coins. I bought a hat that was supposed to be 1100 coins, and it ended up taking 1500 coins out of my inventory.
I am not asking for a refund or something, just saying that might be something to look into.
I reproduced the opening poster's problem with my Balance wizard in the Hat shop at Marleybone.
I bought the Pleasing Hat, base=brown (option on right), trim=brown (option in upper right corner). The price for the hat with these colors was listed at 1176 coins. The shop charged me 1470 coins.
I don't want the coins back, either, as my wizard has plenty. I'm just attempting to step-analyze the problem so that it can be debugged by your programmers.
Sorry, I was at a baseball game yesterday so I couldnt go on, but yeah, colagada pretty much summed it up.
Also saying, there happens to be a bug with wayfinder gear in the bazaar. This might have been fixed already but I am nor sure. But anyway, if you go to red-red wayfinder hat, (this is just for example because right now I am not sure of the prices) then it will say something like 10k. then switch to different colors, then come back to red-red. Instead of 10k, it will go up to its real price. Not sure whats wrong with this but Wayfinder gear is actually expensive, and could anger some people.