Hi!

The maximum number of masternodes I've setup on one VPS is at the moment around 20, but ...

1. Your home PC is not an option ... VPS is easiest (IP ranges, avaliability, ....) and cheaper
2. If your are going to host less than 3 o 4 masternodes don't go the VPS way ... it's better to use a masternode hosting provider
2. If you go the VPS way ... you have to have plenty of RAM and add large amounts of SWAP ... (i.e ram 8GB vs swap 16/32 GB)
3. IPv6 is your friend ...
4. RPC ports have to be carefully arranged ... or even better disable RPC at all
5. systemctl scripts have to be tinkered with to cope with low ram issues
6. The blockchain should to be pruned to save HD space ...
7. And so on ...

Cheers,
Sergien