If you have any "buddies" that have a lathe and can silver solder or braze, that would yield a 90-95% permenent solution. You can even silver solder it and then file and sand it. The fear is that the action that chunked the rod, may have also bent it a bit. Real hard to tool it down to round when the rod is wobbling about! I have trued up bent rods in a press. Not all that hard to do, you just have to remember to go past flat to get it to bend back the other way. Not perfect, but you can get many more years out by back yard repairs. Just degrease it until it is perfectly degreased, then do it again!
On the other hand...
The $150 is by far not out of line for a rod, and it probably comes with a new bushing too.
Are you the original owner of the hoe? If so, do you remember what happened to damage the rod so severely? Normally, the small chips and chunks are caused by rocks falling on the rod, or getting between the rod and hoe body. If that was caused by a pinched rock, you would have heard it and seen the puff of rock dust. Point is, you don't want to put in a new rod (or even repair the old one) and then damage it again right away!
jb