I have read many posting on the forum saying one can get the sensor at Superdrug for GBP 35 to 40. I have checked out a few branches of Superdrug and none of them offer the sensors. Even if one can get VAT exemption, the price directly from Abbott without VAT is above prices indicated from Superdrug. Obviously Superdrug makes a profit so I wonder where do they get their supplies from. So I wonder the rices being mentioned are correct.
You may be looking at some old threads. SuperDrug used to be the cheapest place to buy Libre sensors but a few months ago they hiked up the price. I believe they still sell them but only if you order them in advance from the pharmacy.
I have found Asda Pharmacy to be the cheapest for me. Again, you have to order them in advance but, touch wood, they have had no problems with supply and always turn up within 2 days.
Regarding inaccuracies people are seeing, I too was unimpressed by the Libre at first. However, since discovering the Glimp app (available on Android - I think there is something similar on Apple), my opinion has changed.
Libre measures interstitial fluid rather than BG. It performs some calculations, with a number of assumptions, to convert the interstitial fluid measurement to BG.
The algorithm it uses is proprietary and secret. Therefore, any free app developers have to come up with a new algorithm.
It turns out the algorithm Glimp uses is closer to matching the way my body works.
Furthermore, Libre are "factory calibrated". Unfortunately, my arm is nothing like the "factory arm" so I was seeing huge variations between Libre and finger pricks.
Part of the Glimp algorithm is to take into consideration calibrations from finger prick readings. This significantly helps me.
Finally, interstitial fluid represents BG readings about 15 minutes ago. So, if I am running and my BG is falling fast, the Libre reading (even from the Glimp app) appears to be very wrong.
Any finger prick readings which are entered into Glimp are presented on their graphs. This allows me to visualised readings that are 15 minutes delayed due to rapid changes and close readings when my BG is level.
Libre is not the same as finger pricks and, I believe, the true value of the Libre (or any CGM) is not to save our finger tips but to give us a wealth of trending information to analyse and adjust our diabetes treatment accordingly.
Unfortunately, this is not how it is sold and what many people expect. So they are hugely disappointed.
I would say using Libre to replace finger prick readings is like using a smart phone to make phone calls and nothing more.
Edited to add answer to the title question:
Initially, I had a bad experience of Libre.
Then I learnt how to use it and get the most out of it and my experience improved significantly.
I realised the problem had been with the user not the tool.