100 notes for a simple DCC decoder is a bit silly. Maybe you could simplify things with something like a plug and play decoder, which is the circuit board as well as the chip. http://www.dccsupplies.com/shop/product_info.php?manufacturers_id=61&products_id=1212
DCC Supplies is good for DCC research. They may have something which makes your life a lot easier and help bring the cost down.