is there any other method to add additional IO(IO expanders not aviable/too costly.

For extra pins you have several options
1) use e.g. a P89C668, it has 8k RAM, 64kFlash inside and thus in most applications all 32 pins are free for I/O. Or have a look at the Cygnal F12x seroes (8 I/O ports and 8k internal RAM,
2) A CPLD - it works
3) If execution time permits look at the IIC I/O expanders such as PCF8574 and 8575
4) Use a WSI (ST) PSD chip
5) Discrete logic (address decoder and latches, gates)
6) (output only) an (EP)ROM

Note that all the above schemes constitute Memory mapped I/O.

Erik