I have been successful in create a bare minimum controller using atmega DIP board and .96 OLED to run opentx or ER9x.
This upgrade will cost you only arround 1200 and a loan of USAP to configure for first time.
you can use your existing CT6B case and receiver but with 9 channels and the features of expensive turnigy 9xr.
If you are using telemetry capable module then it can be configured also out of the box with addition of a hardware not over Rs. 100
http://www.rcindia.org/for-sale/atmega128-dip-bare-board/ board
http://www.rcindia.org/for-sale/96-inch-spi-oled-display/ display