Agree too
Small business think they save money when they don't buy a server but the price of support is much higher with a peer to peer network. And you're never sure that everything is backup on the network.
It worth the change of server when you think about the cost for hard disk recovery service and the headache it give.
A right size server for a business is not very expensive. Don't try to have security like NASA just the essential (centralize docs, backup, RAID 1, firewall, AV) for the beginning and invest more later for more security. But always think in your plan that a business can expand even if they aren't supposed, many of them do.