I wasn't ripped off, but I didn't go for the cheapest quote either. I wasn't trying to suggest my installation was typical or what someone could expect to pay in the UK, the point I was trying to make was the cost of labour adds significantly, and overall even if you paid half what I did, it's still too much to expect the majority of UK households to take it up.

My system is larger than typical for a UK home, I also paid a premium to have it installed by a company with an excellent reputation for their work, I'd had a new roof the week before and wanted a high quality installation.

I also went with a company that let me decide how I wanted it installed; other companies wanted to put the batteries in my loft or under the stairs which was an absolute no from me, I don't want them inside my home, and I had them install the batteries and inverter in a brick out house on the opposite end of the property to where the consumer unit is, again, at a premium.

I had per-panel optimisers and monitoring hardware installed, and because I wasn't aware of it until later, I added the bird-mesh on after signing the contract and did get ripped off on that part (NOTE: if you get solar in the UK, and have ever so much as seen a pigeon, get bird mesh).

It's also worth noting that checking today, all of the hardware has dropped in price, my panels are now 20% cheaper, batteries are 15% cheaper, inverter is 10% cheaper, and I imagine installations and labour might be cheaper in the winter than the peak of summer like I had mine installed.

All of that said, the total cost of installation doesn't really matter so much as the ROI, which for me works out at most ~6 years, if none of the hardware fails in the meantime.

EDIT: There's a mistake in my previous comment which I based all of the subsequent numbers on; the cost of 2 batteries + inverter was closer to £5k not £3.5k.