The Sims 3 Maintenance Master Lifetime Reward
Lifetime Happiness Points: 15,000
Maintenance Master may be only purchased by Plumbots. Buying this reward will eliminate the need for Maintenance on the Plumbot. The Plumbot doesn't have to be sentient, but it is easier to get Lifetime Happiness if it is. Once purchased, you could have a Plumbot that needs only Battery Power, fit it with Efficient and Solar Powered, and find that it hardly ever needs attention, especially when working outdoors in the daytime.
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