When my ds wanted guinea pigs I spent a fortune on them!
Decent multi story hutch, a run that attatches to the hutch so then can go outside when they want to. It costs a small fortune in high quality food, bedding etc a month and of course fresh food.
They have tunnesl to run through/hide in and play things in their hutch (balls of hay with bells in to push around etc)
They are moved inside to the garage in the winter but their hutch means they still have a bit to run around in upstairs and downstairs. (and they are brought into the house for a cuddle and run around too)
They are right little characters and love to sit on our laps and stuff their faces when getting nails clipped etc.
Regular vet checks, mite drops etc all mounts up and I think many people just dont think of 'small' animals as costing much.
But I agree a great many people dont think ahead when buying a pet. They never think of the running costs, the vet bills, they things the pet needs to stimulate it or train it, keep it healthy etc. It should be compulsory for anyone selling pets to ensure that the person buying it can prove they have the first idea of what that animal needs. Having kept Gps and rabbits as a child I knew what we needed so it wasnt a problem for us.
My mum had hamsters and they were very pampered, lots of running around in those balls in the living room and they would stop at our feet when they wanted fussing and sit on our laps and get fed and fussed over and settle down on us for a snooze.
(I do know several people with chickens and they are all very well looked after and kept safe and pampered!)