Ethernet Starter Kit for SMT32
You can try it with STM32f7 DISCO. MCU has ethernet controller and MAC and board icudes PHY and RJ45.
http://www2.st.com/content/st_com/en/products/evaluation-tools/product-evaluation-tools/mcu-eval-tools/stm32-mcu-eval-tools/stm32-mcu-discovery-kits/32f746gdiscovery.html
You might get it with around $50.