[REVISED UPDATE, October 23: For awhile, it seemed too good to be true. The full text of Colorado House bill 09-1331, "An Act Concerning Incentives For Efficient Motor Vehicles," turns out to include a cap of $6,000 on the tax credit available for any low-emission car.

The all-important phrase, "not to exceed six thousand dollars," can be found on page 7 of the 26-page act. The cap can also be found in a chart from the Colorado Governor's office within an explanatory page on Motor Vehicle Incentives.

It applies, however, to the 2010 and 2011 tax years--not to the current year. Which means that Colorado Tesla buyers remain eligible for a credit up to $42,000 if they complete their purchase by December 31. And that has caused some upset in Colorado this week.

Our thanks to Gary Gastelu of Fox News, Jay Friedland of Plug In America, and our reader "Ed" for their research assistance. As they say: Buy now, supplies are limited!]

It sounds too good to be true, but here it is: You can buy a 2009 Tesla Roadster, with a list price of $109,900, and pay just $67,800 for it.

At least, you can if you live in Colorado and buy it before December 31.

That's when a special Colorado tax credit, designed to encourage the purchase of low-emission cars, is due to be capped to eliminate the huge credit end.

$42K Tesla tax credit

The measure gives Colorado residents a credit on their 2009 income tax for up to 85 percent of the difference between the price of certain alternative-fueled vehicles and the price of an equivalent vehicle running on liquid fuel.

2009 Tesla Roadstser

2009 Tesla Roadstser

2009 Tesla Roadster

2009 Tesla Roadster

Pricing for the Tesla Roadster starts at $109,000 without any discounts

Pricing for the Tesla Roadster starts at $109,000 without any discounts

The car's materials costs had previously exceeded its list price by tens of thousands of dollars

The car's materials costs had previously exceeded its list price by tens of thousands of dollars

2009 Tesla Roadster, Skyline Boulevard, San Mateo, CA

2009 Tesla Roadster, Skyline Boulevard, San Mateo, CA

In the case of the 2009 Tesla Roadster, the tax credit is $42,083. Which translates to a healthy 38.6-percent discount on a brand-new Tesla.

(That's better than the best incentive you could get on some deeply undesirable model from the most desperate dealer in the country.)

And as anyone who's driven a Tesla will tell you, the car's all-electric power is addictive. The tradeoff: the more power you use, the lower the range.

Boulder store opens Friday

Tesla will open a new store in Boulder, Colorado, this Friday with an invitation-only VIP cocktail gala. Kimbal Musk, brother of Tesla Motors CEO Elon Musk, wrote enthusiastically about the car and the event in a guest article on HuffingtonPost.

Why Colorado? Well, inventor and electrical engineer Nikola Nikolai Tesla spent many years in Colorado Springs.

Lighting up the state

As Kimbal Musk notes, "While in Colorado, Tesla proved that earth was a conductor of electricity, produced artificial lightning with discharges consisting of millions of volts...and performed long distance power transmission experiments that lit up banks of lights around Colorado Springs."

But it's equally important that the state has many wealthy, green-minded residents. The kind who buy Tesla Roadsters.

Especially if the state funds almost half the purchase.

[Huffington Post]