Bought gold as inflation hedge but lost money anyway

I invested $50,000 in gold coins through Goldco specifically as an inflation hedge. Gold prices rose 18% over the next year. I still lost money. How is that possible? Because the coins were marked up over 85% above their metal value when I bought them. Even with an 18% rise in gold prices, the buyback value of my coins was still well below what I had paid. I would need gold to roughly double in price just to break even. The salesman never explained this. He showed me charts of gold price appreciation and implied that my investment would track those gains. What he did not explain was that buying coins at nearly twice their metal value means you are starting from a massive deficit. If I had simply bought gold bullion at 3-5% over spot from a reputable dealer, I would have been up 13-15% instead of down 20%.