from the orlando visitors site:
By Taxi
Taxi fares start at $2.45 and cost $1.40 for each mile thereafter. Sample fares: To WDW's Magic Kingdom, about $20 from International Drive, $11-$15 from U.S. 192. To Church Street Station, downtown, $20-$25 from International Drive, $30-$40 from U.S. 192.
Hope it helps!