The following is assuming play at a high level of difficulty. On the lower difficulties,
If you have a scout at the docks, it is a non-issue. Sell your tools and/or your guns and/or explore enough to hurry the seasoned scout, then rake in the money.
IF you can get to the ruins and villages first, you can make an ungodly killing from one (preferrably seasoned) scout, immensely more than exploring with another unit.
If you can possibly make it happen, do WHATEVER you have to in order to do so.
Once that is happening, you should have enough funds to work from there. You'll want a galleon for big maps, privateer is an option also, if you can get it early. Buying carpenters and lumberjacks helps a LOT.
Suggested money expenditures (per city)
Docks rush, ~200 gold tops
Carpenters/Lumberjacks, 2250-6750 depending how many you need.
TEACHING 3 elder statesemen 2250
TEACHING 3 firebrand preachers 2250
Resource processing specialists 1350-2700 per city on average
Tools - ~2000-4000 depending on buildings and tools prices.
Total cost on average per settlement:
10,000 gold, or 7-8 loads of refined goods., 20-25ish loads of raw materials.
Guns can generally be made far cheaper/easier than they can be bought.
One shot costs:
Galleon x1 (only if there is also enough treasure to pay for itself twice over)
Privateer x1 (If you enjoy piracy)
Seasoned Scout x1 (to get all that loot to begin with)
Extra tools if your late game ore production does not support producing enough of both at once.
One shot income:
sell guns from soldier and any vet soldiers on the docks to the natives for~1050-1250 per 75 guns
ruins/village exploration for an average of at least 250 per ruins/village, close to double that if you have a galleon, double it again if ruins with the appropriate FF. HIGHLY variable.
This pricing assumes you are playing single player, you push for the -25% Europe buy costs FF, and you get him, and nets you a fully developed city which will produce about 80-120 hammers towards an endless stream of cannons or towards ships of the line per turn post revolution, and 13-37 hammers per turn before that (or 112 political points per turn).
Assuming at least one of your colonies has decent ore mining capacity, the same cost will make it an ironworks/arsenal colony that puts out enough tools to put out cannons and SoLs without relying on europe.
Once the revolution happens, the food route will give you a steady stream of new citizens (fodder) and converted natives from all those missions (bait), whilst boosting production and basic crop production, via slavery. You should also have full terraforming and a redundant road network, courtesy of converted native pioneers (which you can have hand in the tools then delete right before rebellion to hit 50% faster). +50 or more food per turn per colony is a thing of beauty when you need warm bodies to pick up muskets.
TL;DR
Both, but mostly food (and production)
. What i meant by food is that it's free manpower if you produce it yourself, and it turns over to a new colonist that you can educate.
