I've had a toyota and lexus, and they dont use the same parts.
if you're getting a toyota that uses nearly the same parts, such as an avalon with premium features, compared to baseline lexus 3 series, the price would be very close. Marketing is a factor, but you're also getting added value even if you dont realize/appreciate it.
And then you read comments like,
"I've found that Toyota uses "twinning" -- using the same chassis for two different cars, the Camry and the Lexus. So basically they're the same car, but with a $10,000 difference in cost....
"The first through fourth generation Lexus ES sedans also shared body styling elements with the Camry, but each generation has seen fewer and fewer similarities between cars. "
"but there is massive scope for variation in internal components, engines, tuning levels, transmissions, suspension design and components (including extended expensive development to further improve the ride over the basic versions) , trim levels and seat comfort, sound insulation/NVH choices of materials."
" https://ask.metafilter.com …tween-a-Camry-and-a-Lexus
"The Toyota Avalon and Lexus ES are powered by the same 3.5-liter V-6 engine, which is also used in the Highlander, Camry and Lexus RX. The 2.5-liter hybrid powertrain is the exact same as well. Mechanically speaking, the Toyota Land Cruiser and Lexus GX are exactly the same, just like certain other Lexus and Toyota vehicles." http://www.t3atlanta.com …between-lexus-and-toyota/
"The Toyota Avalon and Lexus ES are most similar under the skin, as they share a platform, transmissions and engines with almost no modification from one model to the other. Standard in both cars, for instance, is a 268-horsepower 3.5-liter V6 engine that's hooked up to a 6-speed automatic transmission and front-wheel drive -- a combination that's rated at 21 mpg in the city and 31 mpg on the highway in both cars. Opt for the fuel-efficient Avalon Hybrid or Lexus ES 300h, and you'll be driving a 200-hp 2.5-liter hybrid 4-cylinder capable of reaching 40 mpg city/39 mpg hwy." https://www.autotrader.com …ats-the-difference-229780
The engines may not be identical, but I bet that there are a lot of common components shared between engines.
The Germans do it too, in VW vs. Audi.