freedsp analogio alternative

Helo guys.
I'm trying build the freeDsp Infinitas board from freeDsp .cc, It suggest uses analogio expansion boards for adc/dac.
I tryed check option of buil y anlog io modules but I think it's expensive (400usd for pieces all 4)
It have 8 tdm I/o over 1 i2s.
There is any aready assembled and cheaper alternative that i can use?
 
Last edited: