  This white paper offers cautionary observations about the planning and
development of new, large radio astronomy instruments. Complexity is a strong
cost driver so every effort should be made to assign differing science
requirements to different instruments and probably different sites. The appeal
of shared resources is generally not realized in practice and can often be
counterproductive. Instrument optimization is much more difficult with longer
lists of requirements, and the development process is longer and less
efficient. More complex instruments are necessarily further behind the
technology state of the art because of longer development times. Including
technology R&D in the construction phase of projects is a growing trend that
leads to higher risks, cost overruns, schedule delays, and project de-scoping.
There are no technology breakthroughs just over the horizon that will suddenly
bring down the cost of collecting area. Advances come largely through careful
attention to detail in the adoption of new technology provided by industry and
the commercial market. Radio astronomy instrumentation has a very bright
future, but a vigorous long-term R&D program not tied directly to specific
projects needs to be restored, fostered, and preserved.
