I believe you don't have to pay for it monthly(unless I'm confusing it with another engine), if you're ok with not receiving updates, as they won't revoke your ability to use the toolset. Though, you will still need to abide by their licensing when/if you release your game. I'm sure someone will correct me if I'm wrong here, but that's how I've understood things to stand.Is there a way to use UE4 without paying $19/month?
That's correct; you can just pay once, download everything and then cancel your subscription. You don't recieve updates (unless you resubscribe, which you can do at any time) but can continue to use the engine and tools. You still need to pay the 5% royalties. :)