If you have some emotional attachment to that lower - I'm sure it can be fixed... You could probably fix it "ugly" with a dremel, some plastic-appropriate epoxy putty of some sort, and some hand tools. If I were trying to fix something like this on the cheap I'd:
* Cut out the crack to just above the inner surface
* Rough the contact surface of the "V"
* Clamp the loop closed (ensure that the crack is not expanded on the inside edge)
* Fill with epoxy putty
* After the epoxy cures, clean up the outside surfaces with the dremel.
You could probably fix it "pretty" by finding someone who specializes in modifying polymer handguns and spending more than the cost of a new one.
On the other hand... based on what I found on line about that lower - my thought is that @cool arrow probably has given the best answer...