Most leases require one has at least 100/300 BI limits with PD of 100k - though some are OK w/50 for PD.
If you have the wherewithal to purchase or lease a new car you should already have such limits to protect your ass(ets) anyway. So the insurance difference is sort of moot.
Besides, you should carry higher than minimum limits so you can protect yourself against someone with no or little insurance if/when they get you.
You can buy more miles upfront on the lease with a lower residual or worse money factor being the result, too.
While leasing isn't for everyone, it is awesome when it works. My wife drives new Legacy for less than 300 a month, has the dealer change the oil and rotate tires every 7500 miles, with state inspection once a year.
When the companies give cars away like Ford and Honda are doing here in PA with O down low low payment leases,why not drive new every 3 instead of driving cars that are out of warranty and rusty before you mail the last payment in?