Frame Rail repair "cap"

Anybody ever use one of these? I *was* planning to cut out the rusted area and fabricate my own 'patch'. This thing looks like it *might* save me some time... (But it's damn expensive for what it is.) I guess I'm a little skeptical.

MM8151 - 1960-76 Mopar A-Body Front Frame Rail Repair Cap (Rear Section); LH

1969 Dodge Dart Parts | MM8151 | 1960-76 Mopar A-Body Front Frame Rail Repair Cap (Rear Section); LH | Classic Industries