Truble

I am thinking about buying a Honda Accord EX with a V-Tec engine that a
friend of mine is leasing. She leased for 3 years and the car looks great and
has given her no problems. We were all set to complete the deal with the
leasing company when she told me she only changed theoil once during the 3
year period. At that point I hesitated. She has 26,500 miles on the car and
did not overheat or have any engine or oil light come on. If I buy the car
now, change the oil regularly, etc., does anybody have any advice about how
much of a risk I'm taking? What about the engine's lifespan? I'd appreciate
any help. It's more money than I've ever spent on a car and don't want to
make a stupid mistake.