It has 3 cave spiders and one regular spider. It is about 3.5k Blocks away from spawn. I would like around 40k.
Spider isn't best as zombie or skeleton.... So I think the price must be around 15k, I accually don't want to buy them...
The thing with spiders is that they can climb, so it's harder to deal with. I hope you get the spawner sold.
I'm not an expert on spawn grinders, I just know that spider spawns don't sell as well. Look for previous sales for spider spawns and make a price based on what you see. Rather than looking for an average price, look for what prices the customer is happy with.
It's not impossible to sell this type. It's just not as good as the others. (As in what mob appears.) It will sell just fine since it's a quad spawn.