you want something that you probably ant afford...hey thats modern life
You can now buy it and let someone else pay the interest for the time it takes to reapy.
Make sure the loan is finalised by the end of contract and the savings are there to reap.
Conversely say you bought a $10,000 item.
Invest it at say 8.5% comp for 4 years. Without it being compounded monthly, a quick calc suggests that 10k be worth almost 14k...maybe more....pay off the loan and pocket the rest