At $5000 per unit and no further that it sees, a radar net along your coast would not be cost effective.
Per my earlier calculations...
http://gt.toomuchstupid.com/board/t_t36#m6One sector is 60 miles and the radar radius of 25 sectors = 1500 miles
Technically, line of sight is about 10 to 12 miles so this is actually LONG range radar.