Well it ain't easy, but you can get a system quite cheaply based on PC technology rather than minicomputers - $2000 vs $20,000 each, there are some quite respectable systems available. These systems are quite capable and for countries with relatively low levels of traffic, do the job very efficiently. Buying a £28million system would seem to be rather OTT, but I don't know enough to comment on that aspect. By the way ATC systems still work when given just a radio, telephone, pen and paper. Albania started that way and earned enough to pay up front for a new system two years later - well done!! People tend to overcomplicate the job, especially when is ain't necessary especially when the £3.5m system probably exceeds the functionality of the NERC system in variety but admittedly not in number crunching power.