I’ve moved from 6kg Calor to a couple of alternatives.
Bought a 10kg Safefill refillable lpg last year. This is great at around £16 a fill, but ai have to bring it back to Glasgow to fill as there’s now no lpg stations on Cowal or within 50 miles or so of where caravan is. So good price but I needed a backup this year.
The Calor 6kg refill is around £30 from Morrisons, but I noticed Costco has the 10kg Flogas gaslights for £30 refill and around £45 for bottle. The only slight issue with these is they’re 27mm clip on rather than the 21mm or so “POL” reverse screw of the Calor/ Flogas steel or Safefill bottles.
I use gas for midge detergent as well as caravan so figured the “three fill payback” for the gas light vs the Calor was worthwhile.
Gas works out around 80p/ litre with Safefill lpg, £1.50/ l with Costco Flogas 10kg light’, or £2.50/l with Calor 6kg.