I have two cats and spend around £40 a month on food (less if you factor in buying when it's on offer), they eat the Bozita cartons for breakfast and dinner (high meat content, grain free and each 370g carton is equivalent to approx 4 pouches) and James wellbeloved biscuits to snack on.
Bozita cartons are around £1 a carton, so equivalent to 25p a pouch if you were comparing it to pouch cat food. If you buy the 24 packs it works out to 88p a carton, or 22p a pouch. Added to this I always buy three months worth at a time and use the STOCK-UP code on Zooplus (when you spend over £75) which gives a 5% discount.
For dry food a 2kg bag of James Wellbeloved is normally around £15 and I get through one bag a month, but I buy the bigger 4kg bags which work out cheaper (around £21 a bag, which is £10.50 per 2kg), plus when it's on offer I buy a years worth! I went through a period of my life when my finances were incredibly tight so my budgeting has stuck with me!
I give them Royal Canin young male neutered. Per cat, per day: x1 pouch wet food. 90g dry food, so all up x2 pouches and 180g dry.
3.5kg of dry is £26. x48 pouches of wet is £42.
With your prices as they are it looks like you'd be spending more than £70 a month though - 5.4kg of dry (180g for both cats x 30 days) works out to £40.11 and the wet £52.50 (87.5p per pouch x 2 = £1.75 x 30 days). I make that £92.61 in total
I feed more wet than and less dry than you as mine have the equivalent of four pouches per day between them but if you were to keep the feed ratios the same but switch to Bozita/JWB it would cost £41.55 per month in total (£13.20 for wet, being 22p per 'pouch' x 2 = 44p x 30 days) and £28.35 for 5.4kg dry (based on 4kg bag being £21 at Amazon).