1)Say you walk 4km per day on average.
2)An incubator saves you at least 15km (3*5km), so we'll take 16km(for occasional 10k eggs).
3)An incubator is sold at 150 coins each.
from 1) and 2) and 3), an incubator saves you 4 days of walking, which has a value of 150 coins, or 37.5 coins per day. That is, an infinite egg incubator's value is 37.5 coin per day for you.
4)Assume you play the game for the next 2 years.
5)US 2-year risk-free rate is 1.31%, or 0.004% daily.
From 4) and 5), the present value of an infinite incubator is 26,979 coins.
