The red car at Williams looks in about the same condition as mine was when I bought it 28 years ago.
And a good deal better than mine was when I bought it 20 years ago. I would think that at the asking price this could be a very nice car for a hands-on mechanic to own. The bodywork is a bit iffy in places, my main worry would be the state of the inner wing valances and the outer faces of the bulkhead where they overlap.
The point about rolling DIY restorations ending up costing more than buying a good one is in my view a weak argument for 2 reasons:
1. It assumes that you get no pleasure from carrying out the work, which as Spanner Juggler has pointed out, is at least half the fun of ownership of a classic car
2. If you are living on an income, then it's a heck of a lot easier to find a hundred quid every once in a while than it is to come up with a flippin' great pile of cash at the start. Not everyone appreciates the loss of freedom that comes with being in debt to someone.
At the end of the day, we buy these cars with out hearts not our heads. There's no substitute for having a look in person and seeing which one appeals.