I totally agree that you can limit your rust repair expenses if you do it yourself, but having seen the hours that can go into doing a body up to ready for paint if you have to pay someone for even half that you are going to be up there in $.
To me therein lies the crux of the whole question. A DIY complete restoration is achieveable even to someone who doesn't neccessarily have the requisite skills as long as they are prepared to get stuck into learning those skills properly and getting out of their comfort zone and having a red hot go at something.

When I started on my ute over three years ago I:

1. Started with something that was already in VGC as it had been completely corrosion proofed when brand new, garaged, maintained and generally well cared for its entire life both before and after I inherited it. I was very lucky to start with something in such good nick.

2. Already had many of the skills needed to do most of the work myself as I completed a trade as a mechanic many years ago. The skills I didn't have I sought advice from those old school people who did and learnt from them while respecting the fact they didn't have to show me the right way of doing things such as dolly work, welding in repair sections and even the remaining body work and paint. I learnt what I could from them and was prepared that if I made a mistake I would strip it down and start again - which I did do a few times I can assure you.

3. Only used the best quality parts/panel steel/welder/bodywork consumables/paint/materials and even tools I could get hold of as I didn't want any one thing being the weak link in the chain. And,

4. Took the time and patience it needed to get the job done right first time - though I will say I should have hired a paint booth rather than build my own one to paint the ute as it would have actually been cheaper to hire one for a day. In fact while you're there grab the painter as well as they can save you more money than they will cost...

So, three (plus) years later (although there was around 12 months in the middle there I was unable to get any time on the ute at all) I now have the old girl finally in paint, albeit its second top coat - as the first one was not quite the right colour, which I thought was not doing the old girl justice so had to rub it back and repaint it the right shade and being pig headed about wanting to do absolutely everything myself - in total I have spent a few hundred bucks less than 5 grand to get here. I am now enjoying doing the fiddly stuff such as repairing/rejuvenating the stainless trims etc and putting it all back together ensuring that everything is either stripped and cleaned, repaired or replaced as I go. But at the end of it I can sit back and say that I did they whole thing myself.

If you're not sure where to start there are many short courses at TAFE colleges around the place to do with bodywork/welding/automotive refinishing and repair work which are designed to give the participant enough knowledge to be able to return a consistant result. Not only that but should the unthinkable happen down the track after it is finished and you are faced with a repair you would already know your own car inside and out and would probably get a repair you'd be happy with completed for reasonable coin.

Another option would be to find an older retired panel guy and come to an agreement to do a bit here and there - they are about if you look and ask and you can learn from him and keep a lid on your own costs a bit. Doing it yourself is one heck of a lot of work and I can certainly see where and why the costs get going and budgets get blown during a full resto. It isn't for the faint hearted but the satisfaction that comes with getting it right are pretty good, especially when you start to see real progress or someone who knows what they are looking at says to you "geeze, that looks pretty good"!