Actually CR123s are quite difficult to get hold off in the UK and are very expensive as they are usually sold in Supermarkets and Retails chain stores singly, typically costing around $7 a piece. Hence I use rechargeable RCR123s (impossible to find at a retail store outlet) and the occasional Internet online bulk purchase of the primary CR123s at which typically work out at around around $1.50-2. Energiser Lithium AA are generally easier to find than CR123s in the UK at retail outlets. CR123s are therefore relegated to last resort use!