Check your electricity cost and compare that to begin with. I assume that your server will probably consume more than 40 watts on average. You have to factor in idle consumption with the game running. Assuming 40ct/kWh that would amount to 10,57€ per month only in electricity.

Nearly all current printer companies have a model with these properties. The keyword is laser printer. You just need to decide if you need color or can deal with black and white only. My Brother MFC L-2710DW for example suits me well in a similar fashion. It’s network enabled, prints Duplex, we haven’t changed the cartridge in years etc. for below 200$. Just no duplex scan and only b&w. I agree with using the phone for scanning. iOS has inbuilt functionality, don’t know about android.