In my opinion, this is a common mistake made by players – building up a large stock of items in the secondary market that won't sell immediately. A Stronghold for Golems seems unnecessary,
paying 2500 more for three Golems and 8 Gremlins? That's a mistake.
In the secondary market, we build ONLY Golems and invest 1000, or a Stronghold if resources allow.
Here's the save file, by the way. If anyone is interested, they can try playing it further. :)