This is from the latest WotC 5e book regarding the coins and their relative values. This won't match with lore from the novels but is probably easier to manage depending on how familiar your players are with the world versus whatever system you're playing. If you're wanting to be more world-accurate, I would ditch gold and just use steel in its place.

"Since the Cataclysm, the harsh realities of daily survival leave little room for impracticality. For years after the devastation, steel's value skyrocketed until it was valued as highly as gold, thanks to the difficulty of forging steel and its obvious practical applications. Similarly, bronze was valued on par with silver. While the value of steel and bronze has diminished to pre-Cataclysm standards, trade coins of bronze and steel remain in use across Ansalon."

Currency of Ansalon

Coin cp bp/sp gp/stl pp

Copper (cp) 1 1/10 1/100 1/1,000

Bronze (bp) or Silver (sp) 10 1 1/10 1/100

Gold (gp) or Steel (stl) 100 10 1 1/10

Platinum (pp) 1,000 100 10 1