The software, at $30 to $50, also costs less than the frequent-flier services.

"They can buy the book for less than the software would cost, and we can't match the graphics."

The software will cost $15 in January, but for now it is free, a company spokesman said.

The software costs $55 per computer and has been on sale in Europe for about eight months.

The software together with the audio and video boards costs about £3,000.

The software costs $99 at www.x1.com, where a free trial download is also available.

Imagine, for the moment, that your software costs $199.

The software costs the company about $2,500 a month, depending on options.

And the software costs half of what it did just one year ago.

Because each upgrade forces them into the next software price band, software also costs more.