The phrase "as costs fall" is correct and usable in written English.
You can use it when discussing the relationship between costs and other factors, typically in economic or business contexts.
Example: "As costs fall, we can expect an increase in consumer demand for the product."
Alternatives: "as expenses decrease" or "as prices decline".
But rising demand could mean panel prices remain high even as costs fall.
Toyota, Saab, Volvo, Mercedes-Benz and others have developed similar gizmos and, as costs fall, it's likely they will be offered on more mass-market cars, where perhaps they'll prod some consciences.
"Scrapping wind subsidies, rather than phasing them out as costs fall, will simply lead to higher fuel bills for cashstrapped households and make it harder to tackle climate change.
As costs fall the International Energy Agency forecasts that offshore wind alone could provide 18% of the world's energy, displacing coal to power major coastal cities – such as Shanghai – across the planet.
It was only for that one week, but the very fact that the trend – showing income rising as costs fall – is up at all is remarkable at a time when newsprint publishers in Britain are suffering record losses.
"Scrapping wind subsidies, rather than phasing them out as costs fall, will simply lead to higher fuel bills for cash-strapped households and make it harder to tackle climate change".
Even as costs fell, prices rose.
Univision's earnings soared as costs fell at its TeleFutura network, which had start-up expenses in 2002.
The import price index minus oil fell 0.3percentt in September as costs fell for food, business equipment, autos and consumer goods, Labor Department figures showed.
Prices of imported goods declined in October for the first time in six months as costs fell for petroleum and machinery including computers and semiconductors, the Labor Department said today.
NATICK, Mass., July 20 (AP) — The medical device maker Boston Scientific said Friday that it had swung to a second-quarter profit as costs fell from the year-ago buyout of Guidant.
