Looking for the best bargain stocks to buy over the summer? Here are two Alternative Investment Market (AIM) mining shares whose cheap valuations make them worth serious consideration.

Pan African Resources

Investing in gold stocks can be risky. Disappointments at the exploration, mine development and production phases can be common, leading to significant downgrades in earnings forecasts.

However, when gold prices rise they can also offer significant returns. Take Pan African Resources (LSE:PAF), for instance. The business — a mid-tier operator with projects across South Africa — has risen a whopping 40.7% in value since the start of 2025.

Amid signs of reviving gold demand from investors, I think it could be set for further gains. A depreciating US dollar, falling interest rates, and conflict in Eastern Europe and the Middle East are just a few price drivers in play.

I like the idea of considering gold stocks to seize this opportunity. This is because they offer a leveraged return — due to their relatively fixed cost base, their profits often rise at a faster pace than gold prices during bull markets.

For this financial year (to June 2026), Pan African expects all-in sustaining costs (AISC) of between $1,475 and $1,525 per ounce. That’s substantially below the current price of gold, at $3,302. And the margin will get larger if, as I expect, bullion prices rise during the second half of the year and beyond.

City analysts expect Pan African’s earnings to soar 90% during financial 2026, driven by a strong gold price and production ramp-ups at the Evander mine. This leaves the company trading on a forward price-to-earnings (P/E) ratio of 4.7 times.

Underlining the stock’s excellent value, its price-to-earnings growth (PEG) is just 0.1. Any reading below 1 indicates that a share is undervalued.

Base metals producer Central Asia Metals (LSE:CAML) is another AIM-listed mining stock I feel is undervalued at current prices. Its forward P/E ratio is higher but still pretty low at just 8.2 times.

The company makes most of its money from copper, a commodity that’s been in the headlines a lot recently. As part of his evolving trade policy, US President Trump announced plans to put 50% tariffs on his country’s red metal imports. The plan is to supercharge domestic production through the construction of new mines.

The trouble is that the US only holds around 5% of the world’s copper. And on top of this, new mines there take around 29 years to build, according to analysts at ING Bank.

With existing mines becoming depleted in other regions, and a lack of new projects scheduled for the next decade, it still appears that a huge copper shortage is coming that could drive up prices.

I like Central Asia Metals especially because its debt-free, robust balance sheet gives it scope to expand to capitalise on this opportunity. Its recent A$230m bid to purchase North America-focused New World Resources illustrates its considerable financial strength.

Be mindful, though, that copper stocks could come under pressure if global copper consumption temporarily cools.