The cost of some mathematical sites (estimated bizinformation.org):
8.000.000 $ - wolfram.com
372.456 $ - webmath.exponenta.ru (Russian Maple in education)
292.301 $ - maplesoft.com
82.342 $ - exponenta.ru
61.278 $ - webmath.ru
54.895 $ - math.ege
43.302 $ - univ.kiev.ua (Kiev National University)
30.407 $ - college.ru
21.752 $ - Eqworld.ipmnet.ru
16.225 $ - math.ru
257 $ - donnu.edu.ua (my Donetsk National University)
