I've had great luck with PSPrint on-line for many years now with print and many runs of postcards. I know they run small lots on a digital press and normal quantities, 1,000 and up on their Komori Lithrones, very good presses.
They have many options and papers available and their printing is high quality.
If you can properly prepare CMYK files for press, work 100% on line (telephone and payments via phone doesn't work too well!), they can't be beat!
There are cheaper places, but quality, consistency and on time delivery are important to me.
If you are trying to get closer than "pleasing color", about 95 percent of perfect, this is a good value for your dollar.