I only feed high meat/ cereal free foods - I believe that is healthiest and it certainly makes for smaller quantities of unscented poop!
As I came to Purrs forum from Money Saving Expert I looked at the meat content and price per kilo of a number of commercial foods; arguably home made raw is cheapest for the quality. I decided not to buy from Mars, Nestle, Proctor & Gamble, Colgate-Palmolive which rules out most familiar brands of pet food, and I try not to get pouches as they cannot be recycled. Of course I am lucky that Noah is greedy so will eat most animal products, tho he certainly has his favourites: raw, prawns (treat) and Bozita all elicit purrs.
Noah has whichever commercial food is on offer
Bozita pate (K9 Capers, 10% off first order)
Pets at Home Purely 156g tins (when five for £2)
Feline Fayre 400g tins (B&M or Home Bargains)
Orijen kibble (Pet Planet) and Fish4cats kibble (VetUK), both purchased to make up an order of cat litter to get free postage!
And on raw days, most £1.40 per kilo
Raw chicken portions (Tesco Value frozen)
Pork liver, pork kidney, ox heart (Morrisons)
Free range egg (only when short dated or cheap!)
There is little preparation in raw feeding part time, but obviously you really need a freezer - Noah has his own drawer.