MyFonts is not yet authorized to sell this font directly. However, Ascender Corp. offers the font for sale at MyFonts:

Trebuchet®

family of 4 fonts from Ascender Corp.

  |  available for Desktop and Web

$30–$110

You may be able to find this font at one of the following web sites:

• Microsoft Typography: Trebuchet
• Will-Harris: More MS faces for the screen...