Anyone can weld however there are far less people who can weld well!
Some of that forum you can take with a pinch of salt, similar to volksmoan some of the advice coming off there is from people who only think they know it all, although there is some sound advice on there. Its a case of whos all talk and whos actually got some experience.
When restoring a van there are jobs suitable for the beginner and there are jobs that need to be done properly by someone who has some experience. As its not just a case of knowing how to set the welder up and getting going. A lot comes down to how your cutting and fitting the panel, for example not so much of a problem on the vans but for myself when I'm fitting rear quarter panels to a monocoque car you have to look at where the windows are and work out where the stress points are on the panel and then cut your repair section to avoid them. Thinking through your joins can also massivly reduce the chance of panel distortion.
And just because you can stick bits of scrap together on a bench doesn't mean you can weld upside down or vertically, or have the knowledge to manage your heat build up to minimise distortion on a pre stressed panel.
Sometimes does make me cringe to think that there are people out there fitting chassis legs and beam adjusters and think cranking their welder up to max will do the job but wouldn't recognize cold lapping if it smacked them in the face.
But as above between £25 and £30 an hour is a good price for MIG.
This can work out cheaper than investing in your own gear because you've got to look at the price of the welder, if you've got adequate power supply in your garage, price of your consumables, price of your safety equipment (masks, gauntlets, fire extinquisher, welding blanket etc) how much use you'll actually get out of the set up because once you've finished your van are you actually going to get any use out of your welder again, and if you've actually got a useable space to work in. (Welding outside isn't an option cause gasless is crap, and a garage stuffed with old paint tins, meths, oil, petrol powered garden equipment and all the usual garage junk isn't a safe space to work in)
It's also a wise idea to look into some night courses at your local college, the one near me offers a MIG course which is good for learning set up but it really only covers welding on the bench, its a pass or fail format and you get a nice city and guilds certificate but they also offer a vehicle restoration course which isn't as in depth on the welding but covers more on fabricating and fitting panels but doesn't come with any kind of certification. These however aren't cheap, I have done my Lv 1 and 2 City and Guilds TIG (Mild and Stainless Steel in flat and vertical positions) and have spent over £600 on the tution fees. I will however be planning on going back to do Lv2 Aluminium (just so I have a piece of paper to prove I can do ally) and the Lv 3 Steel (because its a year long course and starts to look at the composition of steel more on a molecular level) because they were really interesting courses.