This was my original question, and I haven't looked in 10 days - combination of illness and 'things'. Very interesting dialogue, thanks. I just managed to get a pair of Diadora slightly used shoes on
eBay last night for just over a tenner (stuck to my budget and waited), and they (Diadoras) seem to all retail at over £50.
I got the M520s onto the bike and took a little ride outside the house on the flat inserts - they feel so small compared to 'normal' flats.
However, just couldn't go fast as I'm still waiting for the left STI replacement, so only front brake!
Once I get this part and get it fixed, I'll give my first clipless and cleated shoes a try. I'll be sensible - try unclipping in the house a few times, put on only one at first, and remember the clutch analogy, which is very good, actually. I bought an automatic Mercedes in March, my first one, and found myself pressing a non-existent clutch at first. WORSE was, when taking my old Audi to get MOTd and sold, I actually FORGOT the clutch, after only two months in an automatic, and nearly stalled it twice!
SO: since I'm returning to cycling after a long spell, maybe I can condition myself to clipless fairly rapidly. I think I'll stay conscious enough to unclip a foot before any possible scary moment, and clip back in once past it. Mmmm? I think long hills will be scariest as I'm not fit enough to make it to the top in one go, so I dread stalling halfway up and falling sideways.