Simplify break even point calculation a bit further.
Simplify break even point calculation a bit further.

Closes #18.

senyor/heatshrink,silentbicycle/heatshrink,jordandcarter/heatshrink,senyor/heatshrink,atomicobject/heatshrink,silentbicycle/heatshrink,atomicobject/heatshrink,jordandcarter/heatshrink