Save a GAME after starting with DM 500.000 DM. Now open the savegame with an Hex-Editor and change the Offsets 20a10700 in FF FF FF FF, now you have 4 Milliard Money.
50,000,000 cash
Go to info mode underneath the question mark, and click on one of the towns, then click on rename town and type 'Scrooge' and then click OK. Do this exactly as above and you get 50,000,000 cash to play with. You can do this as many times as you like. Might be worth cutting and pasting it if you want to repeat it.
Hints
Unless your scenario terrain won't permit it, always start up a transportation network with trains rather than trucks. They're faster and carry more.
Place your factories with long-range considerations in mind, straddling several metropolitan areas.
Placing a store right next to an identical one owned by the competition can mean you share up to 90 percent of their
customers.
Use the info icon regularly to view your opponents' product pricing. You can undercut them; they can also deliberately
set out to undercut you.
Tunnels and bridges will reduce travel costs and delivery lag.
Upgrade your transportation network whenever airports and docks become available.