The more I keep them and the more I write about them, the more I see how simple it is to keep these 'pets'.
They need a minimal amount of attention and are cheap to feed.

Over a year, you will save money. Not a lot, but you have the benefit of eating your own produce, knowing where the eggs came from and maybe selling a few spare as well.
This, together with having a vegetable patch can be a real answer to a low cost life situation.

Like many other people in the UK and worldwide, I keep mainly ex-battery hens. They are easily obtained either through The HenHouse (a charity Trust re-homing) or from Battery Farms themselves if you have the 'front' to go for them.

Alternatively they often come up at Auction, where I have purchased them at 5 for £1.
They are extremely scraggy and need some care and attention until they become more 'normal' after 8 - 10 weeks or so and they have their feathers back etc.

If however, this line is not right for yourself, you can buy 'egg breed' chickens such as Rhode Island Reds, Morans ans Sussex Stars etc., from about £8 each.

If you have a small garden, you can keep them in an Ark, moving it around frequently - grass is not chicken friendly!
If space allows, then a fenced off area is good with an appropriate house to match.

Care in so far as protection against predators is paramount. I have nothing against the fox personally, but the occasions I have had to clear up behind him has not been very nice and you feel guilty about it.
Foxes will dig, find any little fault in a wooden slatted shed and can jump to about 4/5 feet. They can, which I know to my cost, also climb a tree on the outside and jump in.

But that apart, I feed 13 chickens on about £3 per week and get between 50 and 70 eggs per week.
The food is supplemented by your left overs and boiled up into a casserole of delight for them.
Like all creatures, they know what they like, dislike, can eat and shouldn't eat. You'll soon get to know.

The other cost saving benefit is they go to the toilet a lot! This can be mixed in with other household waste and you'll have a magnificent compost for your garden.