Financially, check the values on tractorhouse.
Is it a good idea? Nah. I'd keep the excavator and get a used tractor to go along with it. Going to a B2301 with backhoe is a big step backwards from a dedicated excavator.
Of course, you didn't tell us what you're using it for. If you need to mow lawns then an excavator is pretty useless, and a B2301 is pretty useful. If you need to dig ditches....keep the excavator.