GPUs are ridiculously cheap now, compared to how they used to be. You can buy a 3070 from newegg for $599 and they’ll throw in a free monitor to sweeten the deal for you

The 3070 had a $499 MSRP when it launched, I wouldn't call this deal "ridiculously cheap".

MSRP is $499 and that's already inflated $120 over the previously established MSRP.

I would consider a $3070 at $400 to be back to normal.

That’s what I’m wondering. There are a few gpu mineable coins, will miners switch to those, and keep gpu prices high?

Most of the rewards in GPU mining were from Ethereum. There won't be enough money to go around to make it worth the electricity once ETH is no longer mineable. Lots of mining businesses are going to go out of business or switch to Bitcoin/ASICs, and they're going to dump those used graphics cards on the market as they do.

GPU prices are already down. "Sell the rumor, buy the news" and all that.

Down in the short-term. They're still up overall since the 3000 series release.

GPU prices have only started to go down.