If Kim is currently 10 years old, she will be 10+2 =<<10+2=12>>12 years old in two years.
In two years, Sandy will be three times as old as Kim, meaning Sandy will be 3*12 = <<3*12=36>>36 years old.
Currently, Sandy is 36-2 = <<36-2=34>>34 years old.
If Sandy's monthly phone bill expense is equal to ten times her age now, she pays 10*34 =$<<10*34=340>>340 in phone bill expense
#### 340