She didn't reach a billion by not having smart financial advisors. Buying a jet sinks cash into a asset that's losing value whereas financing it allows her to write it the business expenses while putting her cash into something profitable such as her tours.
She can take depreciation deductions and deduct all operating expenses whether or not it's purchased outright with cash or financed. With financing, she can deduct the interest in addition to taking depreciation deductions and operating expense deductions. It would make no sense, though, for her to pay $1.00 in interest just to get $0.50 in tax savings. It would only make sense for her to finance a jet or anything else if she had limited capital and could invest what capital she has in an investment that provides a return in excess of whatever interest rate she's paying on the asset financed. She has unlimited capital so it would never make financial sense for her to borrow money for anything, much less a jet.
Her Father, Scott Swift, is the KEY to her wealth and fortune. Her mother, Andrea, was a MARKETING manager when Taylor got her first record deal at age 14.
Her Dad is a VERY astute Money Manager and Certified Financial Planner. and always was, ever since they first moved to Nashville ( actually Hendersonville, TN ) about 20 to 22 years ago. Before Taylor's success he worked for Merrill Lynch.
Ever since the beginning of her career as a young girl he and her mother have GUIDED her financially and I must say, BOTH has done a TOP RATE job of helping make her successful financially and marketing-wise... her Dad and her Mother are in their late 50's and BOTH have very LIKEABLE non-arrogant personalities.