Go for this trophy on challenge mode to make things easier for yourself
The gold guns are basically just guns that are gold and do a lot more damage. You buy them from the secret area on Gemlik Base (Olantis Orbit), you need to beat Qwark before you can access this area though. You can also buy them in the secret area on Planet Novalis too, here's how to reach those shops:
For the one on Oltanis Orbit (Gemlik Base), you need to have defeated the boss here first. At the very end if the mission there is a runway with a massive tower next to it. What you want to do is go towards this tower entrance. You will notice there is no entrance at the bottom, but in this area you can wall jump all the way up the tower to reach the gold weapon shop (the wall jumping takes a while). For the one on Novalis, they can be purchased via the teleporter near you ship once you have defeated Drek.
Every 4 gold bolts you get, another 1 out of the 10 available gold weapons can be bought from either of the two secret shops. You will need a total of 250,000 bolts and all 40 Gold Bolts in order to purchase all ten, which are as follows:
- Gold Blaster - 20,000 bolts and 4 Gold Bolts
- Gold Bomb Glove - 10,000 bolts and 4 Gold Bolts
- Gold Decoy Glove - 10,000 bolts and 4 Gold Bolts
- Gold Devastator - 60,000 bolts and 4 Gold Bolts
- Gold Glove of Doom - 20,000 bolts and 4 Gold Bolts
- Gold Mine Glove - 10,000 bolts and 4 Gold Bolts
- Gold Morph-O-Ray - 20,000 bolts and 4 Gold Bolts
- Gold Pyrocitor - 30,000 bolts and 4 Gold Bolts
- Gold Suck Cannon - 10,000 bolts and 4 Gold Bolts
- Gold Tesla Glove - 60,000 bolts and 4 Gold Bolts
Upon buying the 10th gold weapon the trophy will unlock.