Windows 2008 r2 Terminal Services administration

I've got a client with a two small, three person offices.  He just bought a Windows 2008 R2 server and was hoping to have one of the offices connect into the server with the two Administrative Terminal services accounts occasionally.  He previously had a Windows 2003 server which allowed this, but when a second person attempts to connect into the new 2008 server, it kicks the first remote desktop session off.  Is there only one administrative terminal services "client" now in 2008 server?

I realize this is not how it was intended to be used, but the limited use of this feature for his employees worked well in the past with the 2003 server.  This new 2008 server is doing no "serving" of anything (no AD, no DNS, no DHCP, no file sharing), other than hosting a small software package geared towards his industry.  The server is basically a glorified workstation that allows more connections than a Windows 7 computer.  He is willing to buy Terminal server CALS, but we are not sure if Microsoft still sells them for Server 2008 r2.  And, if they do still sell them, can you buy just two cals or do you have to get a minimum 5 pack?  Can the server stay in a basic workstation/workgroup role and have Terminal services and cals installed?

Thanks for any help