I remember scrumpy (cider) being cheaper than coca cola in the supermarkets in the UK. I will have to try the cheap stuff next time I'm in the UK. I really like cider now (I was still able to drink beer when I lived in the UK).
Thatcher's Katy is what you want. 7.4%, fizzy, very nice. Weston's Vintage is 8.2% but has a decidedly alcoholic aftertaste. It's more than drinkable but it's strong. The Thatcher's Katy is actually pleasant.
That white cider sounds like your equivalent of goon. If you want to drink goon like a bogan teenager you need to make sure that you don't use a cup - you just hold the cask (or better still throw the bladder away and just hold the "bladder") above your head and open the spout and let it pour directly into your mouth.
It used to be all super-strength lager but that's gone up in price. Any beer or lager over 7.5% has a different tax band - that's really why imperial stouts are costly. One 10% 330ml bottle of those costs, like, £4 or so. A can of Van Pur Karpackie you used to be able to get for well under £1.50. A four-pack of Carlsberg Special Brew used to be about £5.30 (9%), but it's quite a lot more these days. That, along with Tennent's Super, has had its strength lowered to 8%.
I thought of homebrewing but sourcing the apple juice would be the problem. Could be pissed for £2.