If you check their site, their exit relays are not working
https://atlas.torproject.org/#details/F8448313F20BB38C22368213605CB0638A5C9B36https://atlas.torproject.org/#details/9F08F646EE4FAE6346D255F580C17C065911BFBC
https://atlas.torproject.org/#details/B940023907890EB05CCA1334021CBBA5F56C4EFF
Checked this three and it seems their status is running : true
I don't have deep knowledge about how tor nodes actually works.Quote
A 50 USD donation (in cryptocoin equivalent) covers of one day node servers operation .
However this sound really high to host node for one day, quite suspicious. I checked all of them yesterday and none were running. And you are right, It is too high pet day running cost. It shouldn't cost too much to rent a server and most of them are allowing you to run nodes