You can download the binary version and use all of it’s features for FREE. If you want to create commercial apps and sell them, you need to buy the full version of the plugin with source code , I think it’s normal.
As you don’t have it, you have no clue how much work, and time I put into it’s development. Before posting such comments do some research! Similar solutions could cost $500-1000 /app /platform or /year or even more and you won’t get the source code. If you don’t like the price, don’t buy it, you can always create your own integration of AR SDKs yourself.