I've been trying to follow the 20-80 rule lately with my car, especially when it comes to metal work.
You see lots of full restorations that dig into every spot to make sure every inch of rust is taken car of, even smaller areas. That's either REALLY high dollar restoration or a decade's worth of work for busy people.
For 20% the effort or cost you get 80% results. Restoration/power costs both tend to be an exponential curve and the point of diminishing returns is different for everyone. I'm aiming for 40-50% the effort of those insane restorations and hoping for a solid B+ level car the next several years. It won't be particularly fast, it won't be a show car, some rust will still be present and hidden, but the frame will be a bit stiffer, it'll have more power than stock, the paint will be presentable with some minor imperfections, and most importantly, it won't be in the garage until I'm in deeper than I can get out of and never enjoy it.