Logan Labs. Basic test, $20.

http://www.loganlabs.com/

UConn Soil Nutrient Lab $8.00

http://soiltest.uconn.edu/factsheets/HomeGrounds.pdf

I have used the Uconn soil test in the past, it isn't one of the better ones, and their liming recommendations were wrong. Umass offers a very good one for $15 dollars, but again, Logan Labs is probably the best one for $20. In the grand scheme of things, saving 12 dollars by going with the $8 Uconn test just isn't worth it.

I used the soil test from my County Extension Service. The cost was $0.00 and I got the information I needed to make the correct nutrient adjustments.