Just a question more than an answer…
If you are a small company and or team and have no intention to expand thus requiring physical hardware,
Why not stick to the listen server method
Or implement a custom Peer to Peer approach?
Regardless, your own dedicated server at a reputable place (think IBM) runs about $170 monthly to $2000+ depending on the server components and the bandwidth.
Going through non name brand places can reduce that cost to about $50 monthly for the lower end.
On the other hand you pretty much need a Linux or windows server admin on a paid salary to maintain it, so the cost of that is around $100k yearly either way.
(Mind you that it’s not something that anyone can just do, especially to keep games running. Someone in your team should be dedicated to it and either know it, or learn how over time).
As far as implementation work, it’s a long process whichever way you go, which is why a custom p2p is a smarter solution even if you have to actyally hire a network engineer to make it happen - it would lilely cost you less in the long term too…