The most expensive part of guinea pig ownership is the initial setting up, as you'll need to buy all the equipment. But once you're set up you’ll have everything needed to take care of them, after which the daily costs are very low.
This Texel guinea pig won’t cost you the earth to look after
If you buy an Eglu Go Guinea Pig Hutch, items such as food bowls and water bottles come free with the unit. Otherwise you’ll need to buy these from your local pet store.
You’ll need fresh paper and hay for bedding. The hay will only cost two to five dollars for a large bag. Dry guinea pig food will cost around $4 a week, with additional fresh food required (although a lot of this can be kitchen waste such as carrot tops).
The general running costs for two or three guinea pigs will therefore come to less than $10 a week, and far less in the summer when the guinea pigs won’t need as much bedding to keep warm.