First year: what the kit costs
What you pay before the routine starts: bed, bowls, first vaccinations, neutering. See this line on the bill

SureFlap vs PetSafe microchip cat flap
PetSafe's opening is 15 mm taller, and SureFlap's buyers rate it 4.2 out of 5 against 3.1. I'd buy the SureFlap unless your cat is a tight fit.
From the catalog
Beds
Pets at Home Fleece Square Dog Bed Grey, medium
Budget dog bed, own label
£20
Trixie Minou Cuddly Cat Den, 41 x 35 x 26 cm
Cats that like an enclosed bed
£20.19
KONG Ultimate Raised Waterproof Dog Bed, medium
Muddy dogs, waterproof covers
£65
Crates and carriers
Savic Zephos 2 Door Pet Carrier Grey
Cheap carrier for small pets
£28
Catit Cabrio Pet Carrier
Cats that resist the carrier
£43
Kong Ultra-Strong Two Door Dog Crate, medium/large
Crate training medium or large dogs
£54
Ferplast Atlas Car 80 Pet Carrier, small/medium
Dogs to 20 kg, car boot
£86.40
Cat flaps
PetSafe Microchip Cat Flap White
Multi-cat homes, up to 40 pets
£70
SureFlap Microchip Cat Flap White, small/medium
Keeping neighbourhood cats out
£70