White Vinegar for cleaning. Best value - where

What are you trying to clean?
Normal household white for around 40p per 500ml is good for general descaling and light cleaning.
Thereafter go to an eastern European shop and look for the 10 and 20% pickling vinegars. With the 20 keep a window open. Wear gloves with both. If you've ever had a paper cut, the 20 will find it. I've degreased / decoked my diesel engine with help of the 20
Cost? You'll have to visit the shop. Strike a bargain if you need bulk. You can always dilute it later if you want to. 20% will do a furred up kettle in a couple of mins.
Don't bother with adding bicarb unless it is the frothing action you need. Otherwise you are just neutralizing the vinegar. If doing a drain, drop the bicarb in first, and wash it down with the vinegar, then seal your end of the pipe, forcing the foam to the problem (edited)

Just buy acetic acid and dilute it to about 4%; that's generally how cheap white vinegar is made (unless it states via fermentation).

This listing on eBay even says do that.
ebay.co.uk/itm…bYw

I remember on a recent-ish thread about vinegar someone recommended 'Polish high strength white vinegar' - maybe this 'cleaning vinegar is the same? From MSE:
Most of the white vinegars I'm seeing on Amazon have 5% Acetic Acid, though if you search by % or use terms like 'high strength' many come up.

Might be a handy list for someone! Surprising Vinegar Uses: White Vinegar Uses | Reader's Digest (rd.com)
- I'd double-check the coffee machine descaling recommendation, not suitable for bean to cups / this tip is more for filter / drip machines

Slight tangent - Who knew there were so many vinegars (though this is from a US restaurant site and more for foodies) 13 Types of Vinegar: Uses, Benefits, How They're Made (webstaurantstore.com) (edited)

Amazon!

Depends how much are you looking to get, the odd small bottle? Gallons? Higher strength actual white vinegar? Or basic distilled do? (edited)

I read this as white wine vinegar

Chinese cash n carries like Hoo Hing and Wing Yip I'd have thought

Aldi or Lidl work out good value for their little bottles, even if you want a lot.

Cheapest I can see 2 x 5L on Amazon at the moment is £7.99 (2 x 5L can go down nearer £7 from some sellers at times, going by this thread)
Spirit White Vinegar Food Grade Acetic Acid Liquid for Household Cleaning, Cooking, Baking and Pickling (5L, Pack of 2) Sold by Bilssify_1 - '5% acidic content'
amazon.co.uk/gp/…mbc (edited)

My mouth is watering reading this thread 😳