[EdT]

My wagon is far past yours in rusting away. I give it maybe two winters, maaaaaybe three if I'm lucky.

As others have pointed out, rust repair is not straightforward. Before even starting, I would carefully evaluate all other parts of the car for rust. You might find more than you expected, little patches here and there that will only grow.

I won't do rust repair, it's not worth it, nor will it last on a daily driver. Sure, if it's a collector that you only drive on sunny days, fix up the body, it's probably "worth" the money spent, and it shouldn't deteriorate much in the future. Daily driven, in winter, the repairs are likely not going to last, unless really really done properly (expensive if it actually happens). And other parts will rust anyway.

 

[EdT]

I am not going to look too closely at my rusting 9-5. I don't think it's as far gone as yours....but it might be. Well, who needs rocker panels anyway?

 

[EdT]

That's interesting. A body shop I stopped by estimated two grand to do my rear wheel wells and repaint, including driver's door that doesn't quite match.

I assume from your pictures that you did the rocker panels as well. I think that's a hidden (and not estimated) issue on my car.