I purchased a business in 2015 for 35,000 dont I get to write off $5000/yr for the inital cost of purchasing?

It depends on how you set it up on your depreciation schedule. 

It's depreciated differently than say, a shovel or a computer.  The life of your purchasing costs is going to be longer than those two items mentioned above. 

Here's Publication 946, which may help you to classify the purchase of your business.