That's something I don't like about Minecraft. They need to develop this further for the price to be fully justified to me. As it is right now, my young son gave up on it at about hour 4 and I had considered refunding it but I decided to give it a go myself, the next 4 or so hours were pretty misreable, but then stuff started to click for me but still. I don't really consider $18 to be expensive for this AS long as they continue to develop it, right now it does feel like a really nice mod for Minecraft and I'm not sure what they can do to it to get out of that feeling. I bought Minecraft in pre-alpha, cost about $12.50 but I bought two copies, one for me and one for my partner so about $6.25 each with the promise that all future versions would be free (we'll have to see how that turns out when they want to swing out a Minecraft 2 I *wish* early access for a buggy game was much cheaper, but I'm old enough to know what it's not. I bought it originally for $24 as I recall.
Minecraft is $27 right now, Java Edition (multiplatform).