If i understand it correctly we could use 5k of it in teh first year and write the rest of equally over 15 years?
No, that's not correct. What you are citing applies to business start-up expenses. The purchase/takeover of a client list is not a start-up costs. It's an acquisition cost. Since you "acquired" what is essentially intangible assets, the total cost gets entered in the Business Assets section and amortized (not depreciated) over the next 15 years. So the cost will be deducted and not depreciated, in equal amounts over the next 15 years. Take note that the first year deduction will probably be pro-rated by the program to account for the fact that you did not have this business or the client list for a full 12 months of the tax year.
