Board Thread:Questions and Answers/@comment-771828-20140803111839/@comment-50.65.109.111-20170625172828

The yields (factoring in resale)

WAGR - approx 32 gold / 1 exp point

Cornelius Railway worker, Antonio El Drac, and Ethan II Gravity Generator - 40 gold/exp pt. (These are THE BEST options available in game from contractors. Excluding Giovani's fountain, because it's so small)

If you send your Int Trains to Cornelius/Antonio/Ethan II, you get at 30% bonus in passenger (and therefore gold) delivery. Generally, it can take a decent amount of time to buy the Railworker (615 Mil gold), 1/6 the time to build El Drac (100 mil gold), and about 1/120 time to build the Generator (5.5 Mil). The time it takes to build the generator, constantly buying and selling, can be a drag, so if you're pressed for time, leave out Ethan II on your trips. Otherwise send all your excess Electric trains to Cornelius and Antonio.

I'm currently send 12-15 trains each round to all three destinations (all trains are at least 80 power, some sets, with the best wagons I've acquired thru SO and VO. This is currently netting me 10-15 mil exp each round, multiple times per day.