This is a change I decided while looking over that achievements. As it stands, if you spend your money just right at the beginning of the game, you can have 6 businesses of one kind each upgraded a couple levels within about 24 hours thanks to the current business achievements. While this is quite nice, I think it lets you do too much too fast. I was going to lower the reward for business achievements, but instead I decided to raise the price of businesses a little.
This is good I think, it kind of bothered me that it was so easy to roll achievement dollars back into businesses to generate funds so easily at the start ... handy, for sure, but far too easy I think.