A donated or second-hand machine - 1GHz CPU, 768MB RAM, 20G HDD, palm-size 8 port switch (not a hub) and a bunch of terminal hardware, viz P133/32MB/zero-HDD.
Yes, you WILL need that much RAM. Buy some more if you don't have enough.
You should be able to beg the server off someone as they upgrade to the latest all-singing-all-dancing machine.
Definitely do not pay for the terminal hardware - it is junk.
It will be slow and hard to configure, but we will be here to help.
best, Steve