Some quality products like the toyota red coolant actually work out to save you more in the long run. Instead of having to later replace corroded radiators, water pumps,thermostats,heater pipes etc...
Better safe than sorry

reuby,
from your experiences i would say the castrol you mentioned is a quality product even though not expensive.whats the lifespan of that particular coolant?thanks just to get a comparison to other coolants lifespans.