This is no longer true. The Toyota hybrid batteries last well over 100k miles. In fact, for most Prius, the battery has lasted well over 200k miles! In fact, in California, hybrid batteries have a warranty of 10 years, 150k miles.
Replacement costs is under $2000 these days, including labor...and this is with a brand new battery. You can search for a used one for under $1000. And with hybrids, you don't need to replace your brakes until near 100k or beyond...so, you save money on that end. Worst case scenario...you need to spend $2000 every 200,000 miles beyond routing oil changes...not necessarily a bad investment!