NEW YORK - Does anyone get excited about buying a couch? I can't say the prospect awakens the impassioned consumer in me.

Maybe it's a matter of optics. Take cars, for instance. Put a Porsche next to a Kia and it's easy to spot the former's superior design and engineering and understand (to some extent) its inflated price tag. But show me two sofas, at the low and high end of the market, and I can't see much difference between the $700 couch at Bob's Furniture Barn and the B&B Italia model that will set me back more than 10 grand. Both look more or less like cushioned boxes. Barring gymnastic mistreatment, both will likely still be upright 20 years from now.

There are those who would argue that a great piece of seating lasts a lifetime, but who wants to make that kind of commitment to a couch? Is it going to be passed down to successive generations? You never hear children fighting over who gets the sectional.

And yet, now that I need a new couch to replace the latest one I characteristically bought cheaply and treated poorly, I find myself rethinking my approach. It might be worthwhile, after all, to find out what goes into the design and construction of a high-end sofa as opposed to a budget model, and whether it's worth investing the money.

Thinking of sofas as interchangeable is wrongheaded, apparently. Magnus Breitling, director of product management for chair-maker Emeco and formerly with Vitra, a Swiss furniture company, set me straight on the subject of luxury sofas.

"There's a lot of intelligence that goes into the product, not just in construction but in sourcing," Breitling said.

But then, one reason manufacturers like Ligne Roset and Vitra charge significantly more is the involvement of a top designer, Breitling said.

"You're investing time and money in playing Ping-Pong with the designer because they have a vision."

For me, a more persuasive argument would be superior construction.

In a budget couch, New York upholsterer Kayel De Angelis said, "you could see plywood frames that are stapled together, with foam rubber inside. Frames made in that way - give it a year or a little longer, and the arm might be loose."

The frame of a custom or high-end sofa by a manufacturer, he added, is usually a hardwood like ash or maple held together with glue and dowels or tongue-and-groove joints.

"The joint is just as strong as, or stronger than, the wood itself," he said. "And, then, the multiple layers of the upholstery won't degrade the way foam rubber will."

Breitling pointed to the cushions and outer layer as another point of difference.

"The life cycle of the fabric or leather is much longer with an expensive couch," he said. "Foam gets compressed and releases, and with time, the foam is wearing out."

So how do I know whether I am actually getting my $10,000 worth?

Annie Elliott, an interior designer in Washington with strong opinions on the subject, believes a five-figure couch isn't just hype.

"Unlike fashion, where you pay for style and name but not necessarily construction, with a sofa I think you are paying for quality," Elliott said. "You're getting things like feather and down cushions as opposed to foam."

But you can buy a perfectly fine sofa, Elliott said, with a solid wood frame and feather-wrapped foam cushions, for as little as $1,500 if you find a deal. And she doesn't see much difference in sofas priced in the midrange (say, between $2,000 and $4,000), other than shape or slight differences in fabric and cushion quality.

"Now, when you get below $1,000, that's where I think you have to be careful," Elliott said, because manufacturers are probably cutting corners to keep the price down.

Although Elliott sees the value in investing in a top-notch sofa, she believes it's a purchase that's conditional on your life stage.

"If you're in that nomadic stage, moving every few years, sometimes without movers, you don't want to invest in an expensive sofa," she said. "It's going to get trashed."

What if you're a bachelor settled into an apartment but don't want to buy an expensive sofa a future wife might hate?

Elliott scoffed at the notion.

"I think it's depressing to buy everything quasi-disposable," she said, and wait for someone to "rescue you from mediocrity."

For me, I'm still looking.

Is an expensive sofa worth the investment? Wouldn't I be terrified to sit down on it?

And yet, true, the Kia might be cheaper, but in 20 to 30 years the Porsche is the car that will still be turning heads on the road.

Tim Springer, the founder of Hero, Inc., which consults with companies on ergonomics and environmental design, said couch shoppers often make the mistake of simply plopping down, wiggling around for less than a minute and then making a snap decision.

"You wouldn't hop in a car in a showroom for 15, 20 seconds, hop out and say, 'I'll take it,' " Springer said. "But you see that all the time with furniture."

He offered some tips for choosing a sofa that will not only hold up but be comfortable for years to come.

• Take it slow: Watching a movie at home, you might log two hours on the couch.

"So 10 minutes in a store is not much to ask," Springer said. "If you're comfortable the first minute, but three to five minutes in you go, 'You know …' that's probably an indicator that it might not be the best fit."

• Check under the hood: Ask things like what the frame is made of, how it is held together and the type of cushion foam used. If you're not satisfied, don't be afraid to ask if you can lift up the couch.

"If I'm going to spend top dollar," Springer said, "I'm going to turn it over and look."

• Do the flex test: If you can torque the frame, it might be a sign of poor construction.

"Some of it is physics," Springer said. "If you have a very long sofa, you could probably flex it. But if the back or the arms move easily, that's probably not a good sign."

• Treat the showroom like your living room: "Don't let the salesperson pressure you," Springer said. "It's your money, after all. You have to get into your own head and say, 'I'm here because I want to evaluate this.' Be pretty critical, because that's your chance to make a decision."