Active electronically scanned array (AESA) radars look to be approaching some major reductions in cost as the technology matures(paid subscription required). They are looking at the cost to drop from $5 million/m² to $500K/m² so “cheap” is a relative term.

Additionally, the use of an AESA with a parabolic reflector setup can give a much larger effective aperture, and hence resolution. It’s called AESA-fed reflectors (AFR), and it’s less agile than pure AESA, but a lot cheaper.