Significantly less than the cost of the infrastructure. Running an LN node is a way to bleed sats via force closes and HTLC timeouts, and burn energy while being idle for most of the time. It’s a jolly good time.

I intend in the future to get to run my own node, but right now I'm just in the state of studying and maybe renting a cloud node to get more knowledge of the management.

I like to read and listen about nodes but I just enjoy LN and keep my eyes on development. Nodes are out of my reach.