Reduce Harvester cost from $1200 to $1000

This is to make opening with a factory instead of more refineries a bit more feasible. 

Given that there is a maximum limit of how many harvesters can operate from a refinery in TD, lowering the price shouldn't be a problem, since there can't be harvester spam. How many refineries you have will limit how many harvesters you can effectively use. 
By comparison, RA harvester is $1100.