Whoa 13 months would be quite a long time to wait for an upgrade, yes. There are several things you can do to shorten this. First, don't wait to buy a bug mine. Buy a 2nd Starter mine instead. They're much cheaper at 4,700g. Then buy a 3rd Starter mine, flush them all out with standard-quality equipment, and you'll be cruising at about 100g per day.
There are still many ways to make this go even faster. Buy some vehicles and trade between cities (just use cheap yellows to start since those can only be attacked by other yellows).
Or get some melds and be a worker. Wages in Harmond are currently 35g/week if you have 20 melds, 60g/week if you have 30 melds and go up from there. They're significantly higher in other cities but melds are more expensive there, so you'll want to crunch some numbers before deciding and being a player-driven market, things can change.
Or you can ask on the forums for a gold loan. Even if you can only get enough money for a 2nd Starter, that will get your income up in a hurry.
Then there's the classic "buy-low, sell-high" game that you can play with any item on the market. Put some low bids in, wait for them to be filled, and resell the items for a higher amount.
Cannon ammo is one item that's in serous need of liquidity right now, and manufacturers will gladly sell to cheap bids as their production lots are 100 items each. That'll make good use of your inventory slots which would otherwise just hold your 1g yellows.