I spend quite a lot, my mum agrees i spend too much on my guinea pigs, but they are my hobby and my passion just like she spends loads of money on crafty things, i spend it on my piggies, ive got 7 piggies i buy food in bulk now cheaper so i get 5 x 2kg bags of food, 1 2kg bag will last me about 2 weeks ish, and that £4.29 a bag.
i get 3 huge bags of hay every 2-3 weeks from a farm shop which cost 1.75 each
shavings i get in bulk too and its £5 for a bale which lasts me 2-3 cleans of the girls huge cage, my boys have towels/fleece method so i dont buy any bedding for them except when i bought all the towels/sheets.
i spend around £9-12 on veggies a week, and i sometimes have to top up their veggies during the week if they run out of something
they have numerous toys and I'm always buying them new ones, and treats i buy grass seeds etc too so i can grow them grass, so i do spend quite a lot on them.