A cheaper method would be to use a stratified sample with urban and rural strata.
From the en.wikipedia.org
Taking Part uses a proper randomised, stratified sample of households visited by trained interviewers.
From the guardian.co.uk
It is approximately a 20 percent stratified sample of all U.S. hospitals, accounting for about 90 percent of all discharges in the United States.
From the sciencedaily.com
The poor readers were 25 fifth-graders taken from a stratified sample from schools in Allegheny County, which is home to Pittsburgh and a number of its surrounding municipalities.
From the sciencedaily.com
A large, stratified random sample of individuals from the census list aged 55 and over was selected.
From the sciencedaily.com
The sample was stratified by age, gender, race, education, and region.
From the guardian.co.uk
The sample of schools was selected using a stratified probability methodology.
From the signonsandiego.com
It is based on interviews with more than 2,100 CFOs from a stratified random sample of companies in more than 20 of the largest U.S. markets.
From the sacbee.com
A stratified random sample of Harris Interactive's online panel was invited to participate through a password protected e-mail invitation.