While shopping at Ikea last week, Liz Halsall confronted a dilemma that's confused many shoppers the past few years: what light bulb to buy.

The incandescent bulb of Thomas Edison is phasing out of production, thanks to a 2007 federal energy ­efficiency law. And when consumers now enter the lighting aisle, they face bulbs of various shapes, technologies and price points that make comparison shopping more difficult.

On top of all that, one new type of light, called a light-emitting diode or LED, is undergoing the rapid transformation of price and capability that shoppers more often see in computers and smartphones. It will last far longer than other light bulbs, but it's not as cheap, though some prices are now a fraction of what they were five years ago.

As she sized up all the lights at Ikea, Halsell, an interior designer from Mendota Heights, hesitated over style and price.

"I prefer incandescent," she said. "I guess it's because it's what I grew up with."

LEDs use 75 percent less energy and last 25 times longer than an incandescent bulb, according to Energy.gov. Replacing five of the most commonly used bulbs can save $75 in energy costs per year, according to the website. An average home has 50 to 80 light bulbs.

The change away from incandescents forced shoppers to flip their cost expectations. For decades, people bought cheap bulbs and that cost more to run. Now, they're encountering bulbs that cost more but are cheap to run.

Halsell examined two LEDs because she thought the fixtures she was buying would only accept them. But the prices of the LED bulbs, $4.49 and $6.99, made her pause. "These prices are high, and I don't think they last as long as they say they will," she said.

She's not alone in her reluctance. Consumers are increasingly turning to halogen bulbs, despite their poor energy consumption relative to LEDs and another, compact fluorescents, or CFLs.

Market data shows that sales of halogen bulbs rose sharply last year while CFLs fell. The average price for both halogens and CFLs is around $2, well below the LED price average of $10.70. Some ­market watchers have predicted LED bulbs will take off when their average price reaches $10, though others think they will need to fall much more.

"Incandescents were only 50 cents to $1 each, so I think LED bulbs need to be about $3 before consumers will consider buying them for their entire home," said Kim ­Sherman, senior product portfolio manager at Xcel Energy.

The Minneapolis-based utility encourages Minnesotans to purchase LEDs with subsidies that are reflected in the price at the cash register.

Jerry Neid of Plymouth said he started buying LEDs a year ago. "They're new and high buck, but I love them, especially the daylight ones," he said. "I'm an LED guy now."

Neid has purchased only about six LEDs so far, and like many people, he's slowly making the switch as the incandescents in his house burn out. Standard incandescent bulbs from 40 to 100 watts were phased out of production after President George W. Bush signed a law to raise energy efficiency. Hoarding was common as retailers sold out of their final shipments of incandescents.

But now, LEDs are making significant gains. In 2014, the number of LED bulbs sold doubled in North America and revenue rose 50 percent, according to Will Rhodes, research manager for LED at IHS Technology.

Prices for LEDs are falling nearly as fast as computer chips. Experts note LEDs are made from some of the same processes as chips. In 2009, a 60-watt equivalent bulb from Philips was $40. Home Depot now sells a more energy-efficient version from Cree Inc., an early innovator in LED technology, for $6.97.

The low-price leader on LEDs in the Twin Cities, Ikea, does not rely on subsidized bulbs. Ikea now sells about 20 varieties of LED bulbs, including standard A19 40-watt equivalents, from $4.49 to $8.99. The Sweden-based home furnishings retailer will convert all of its lighting to LED next year.

"Everyone should be able to afford to live more sustainably at home, and we will make sure our LED prices the lowest on the market," said Steve ­Howard, chief sustainability officer at Ikea, in 2012. In another sign of its price aggression, the retailer has announced a 50 percent-off sale on LEDs next weekend.

While consumers may be attracted by low prices, others are concerned about the quality of low-cost bulbs. CNET.com, which publishes reviews of consumer technology, describes Ikea's LEDs as appealing and an excellent value but added, "They aren't as bright or efficient as their competitors, and they don't come with a warranty."

Manufacturers also are overcoming another impediment. Some of the first LEDs a few years ago were odd. They had fins to vent heat and color filters to make their light more like the light of an ­incandescent.

"The early LEDs were Frankenbulbs," said Mike Watson, vice president of product strategy at North Carolina-based Cree. "Consumers found the claw and mushroom shapes as repulsive as their price points."

John Bell, construction manager with Klodt Development in Minneapolis, thinks that LED is the way to go now that prices have come down and their aesthetics have improved.

"I don't like CFLs, so I bite the bullet on the higher cost of LED," he said during a recent trip to Menards for bulbs.

They don't work every time for him, though. Bell left the store empty-handed after he couldn't find an LED in a decorative bulb shape.

Minnesota construction companies may soon be forced to install more energy-efficient bulbs in residential new construction. The 2012 Energy Code, which takes effect Feb. 14, requires a minimum of 75 percent of bulbs in permanently installed lighting fixtures to be "high efficacy lamps [bulbs]."

The Builders Association of the Twin Cities has asked to delay the rule because of other elements, said President Shawn Nelson.