i'd check around on the parts pricing, i'm sure you can get a better deal than that
but the time frames mentioned between servicing is correct
I usually try and stick to the 250hr interval under normal use conditions. If its in a hostile environment (dusty yard) then you'll have to play it by ear and estimate the intervals depending on the condition of the oil and filters after changing them out the first time. It may require more frequent servicing under extreme conditions ;o)