Gold is barely difficult to get. Farm Ramboy for a week straight and you’ll see a couple hundred thousand. (if your mech is weak).
Or farm Overlords Den Mission Six insane, tons of gold per 70 fuel run. If your mechs capable of OD6 then you can wait for the gold portals we’re supposedly having every monday now.
Gold is one of the easiest things to get in this game. Hell even PVP now gives you like 14k each win. Grind and you’ll get gold.