I've never considered maintenance insurance/plans to be worth it. After all, the washing machine that has just broken cost £40.00 five years ago and I've just replaced it with one that cost £30.00 - less than two months maintenance plan cost. If that goes for a couple of years I'll be chuffed.
Instead, put £20.00 a month in a savings plan or something, unless you're incredibly unlucky, I reckon you'd accumulate a tidy sum over a few years. After all, what do you think the people that provide maintenance plans are doing - they're not doing it out of the goodness of their heart.
As to it costing £150.00 or more to fix a washing machine - how ridiculous, you can buy a brand new one for that, it's no wonder we live in a world where it's cheaper to throw things away and replace them, rather than repair them. I appreciate that this is partly due to these things being built in automated factories or parts of the world where labour is very cheap, whereas the person that has to fix it here in the UK has to make a living and pay UK prices. But another problem is that many of these things are just not made to be easily repaired, with parts that fail virtually inaccessible, or part of sub-assemblies that can't be disassembled plus a massive mark-up on spares that renders repair uneconomical.