Rebuilds that don't last must be either a bad build or improper engineering.
If done right it should be if nothing else reliable.
But the fact of the matter is yes it seems expensive. Then again, if you threw in some forged internals, work the head, do the cams etc then the cost quickly go to R30k.
Same with a RB. R10k is the motor. But do do a complete conversion properly I think you'll be looking at R50k min.
Right now I'm contemplating just dropping in an import. R6500 and I get to have a complete spare motor that is still functioning just fine.
How many have used import motors and what have your experiences been? Please do list how much you paid for it and which engine importer you bought it from.