Irish writer Oscar Wilde defined a cynic as a "man who knows the price of everything and the value of nothing."

But a sentimentalist, Wilde wrote, "is a man who sees an absurd value in everything, and doesn't know the market price of any single thing."

We think we've found a balance between the two. Below is a list of seven important price points from this year that are proving the value of cleantech. 

30-year solar PPA: 6.9 cents per kilowatt-hour
In July, Palo Alto's municipal utility approved 80 megawatts of solar PV projects that will supply 18 percent of the city's power load. By purchasing the power for 6.9 cents per kilowatt-hour over a 30-year period, the city secured one of the lowest power-purchase agreements recorded. "Try building a new nuke or coal plant at that price," said Adam Browning of Vote Solar.

LED street light: $99
After rolling out an LED bulb for less than $10 at Home Depot, lighting company Cree is now offering a $99 LED streetlight with a payback of less than a year. With manufacturers continuing to decrease the cost of producing LED lights, the price of products continues to fall, opening up previously inaccessible markets for the technology.

Lifetime cost of an electric vehicle: $44,325
The upfront price of electric vehicles is still a major barrier for drivers. But when the Electric Power Research Institute compared the lifetime costs of EVs, plug-in hybrids and conventional cars, it found that the Chevy Volt and Nissan Leaf cost less than 10 percent more. When factoring in tax credits, the cost of gasoline and maintenance, EPRI found that the average EV only cost $44,325 over its lifetime.

Multicrystalline solar module manufacturing: $0.36 per watt
From 2010 to 2013, leading Chinese solar companies dropped the cost of producing a multicrystalline solar module by 54 percent down to $0.50 per watt. GTM Research Senior Analyst Shyam Mehta recently outlined how leading Chinese solar companies can continue the trend and bring the cost of producing a modules down to $0.36 per watt. The answer: advances in conversion efficiency, reducing yield loss and automating production lines.

Intelligence in LED fixtures: $0.05 per square foot
There's a rush to make controllable LEDs more intelligent by embedding sophisticated computing platforms in lighting fixtures. Sounds expensive, right? Not necessarily. As companies develop new integration partnerships at the manufacturing level, Digital Lumens CEO Tom Pincince said the cost of embedded intelligence is moving toward $0.05 per square foot -- down from more than a dollar. "This will bring us from dollars to dimes, and eventually from dimes to pennies," said Pincince.

Centralized solar inverters: $0.14 per watt
Just like we've seen in the solar module market, inverter prices are falling quickly due to shifting demand for product and oversupply. As a result, GTM research projects that centralized inverter prices will fall 10 percent annually through 2016, hitting $0.14 per watt by 2016. That's going to put major pressure on inverter manufacturers. But the market should moderate after 2016, alleviating some of that pressure after a period of consolidation.

Decrease in the price of energy efficient appliances: $12
Conventional wisdom says that efficiency standards will raise the price of products. In some cases that's true. But in the appliance sector, it turns out that standards have actually reduced the price of dishwashers, dryers and air conditioners. According to an analysis from ACEEE, nine recent Department of Energy (DOE) standards have dropped the price of appliances by $12 on average. That's exactly the opposite what DOE said would happen. When the rules were being crafted, the department estimated a $148 increase in the upfront price of those products.

(For the cynics out there, keep your eyes peeled for an article on price points that some in the cleantech business would like to forget.)