Lance Bass can save his financial advice for someone else -- because One Direction singer Harry Styles claims he didn't drop $200,000 on a brand new Ferrari ... he just rented it for a day.

We posted the photo -- showing 18-year-old Styles rolling around Hollywood in a brand new Ferrari California this weekend.

Former 'N Sync singer Lance Bass had some words for him too -- telling us last night, a Ferrari is a TERRIBLE investment at this stage in Styles' career. Lance said Styles should be focusing on saving his money, not throwing it away on cars.

But Lance wasted his breath -- because a rep for Styles tells us, the young singer is a whiz with his money ... and only rented the Ferrari for a few hours ... as a rare treat.

We're told the Ferrari cost Styles a few hundos at most ... which he can probably afford.

From TMZ.com