More Options for Reading Thermocouple Signals
Both of those chips are just doing amplification of the thermocouple voltage.  They have some features like temperature compensation, open lead detection, and filtering, but not a whole lot more. They're expensive because they're not commonly required, not because their function is difficult. 

You could get reasonable results with a single rail-to-rail amplifier.  Using the non-inverting configuration:



(where Vout ~= Vin(1+R2/R1)), select a large value for R2 and a small value for R1 to get the low-voltage signal into a range that can be read by your microcontroller's ADC pins.  

Temperature compensation can be implemented in software, open lead detection can be achieved by a very high value pullup or pulldown resistor (which will cause the amplifier to saturate on one of the rails), but filtering will require some of that analog work you didn't want to do.