Correct me if I am wrong, but 20$/month for a node is very expensive. No? I was reading somewhere that you can pay 19$/yr for a full node.
Q: $20? That's too much, you can find cheaper VPS providers!
A: I know, but servers with less than 2GB of RAM tend to crash the bitcoind daemon
As OP said, bitcoind requires around 2GB of RAMin order to function properly. $20/mo is a somewhat medium price for it.
So $19/ye... kinda hard to pull off.