CrossRoads:
How much on e-bay?
You can get from distributors new for $4.40 & $5.11
https://avnetexpress.avnet.com/store/em/EMController/LED-Drivers/Maxim-Integrated-Products/ICM7218CIPI/_/R-1324507/A-1324507/An-0?action=part&catalogId=500201&langId=-1&storeId=500201&listIndex=-1&page=1&rank=5
the cheapest ICM7218 I can find on ebay is at 9$ with shipping costs. It's cheaper from distributors as you say but I usually buy almost exclusively from ebay because I don't want to wait to make a big order and save on the shipping costs from a distributor. MAX7219 is as cheap as 1.5$ on ebay. It's just so seducing lol
But anyway, I decided to refrain from buying another led matrix now just to use a MAX, I think I'll use what I have: 595's and 2803; that is the good old way.
Riva:
Another cheap chip to consider is the WS2801 with a shift register.
yeah I saw this chip recently and it seemed pretty cheap, especially considering it provides I2C. But is it suitable for the application? It has only 3 channels, so to deal with a row or column (8 leds) at a time, I will need 3 of them (?)