Your link does not work, but that seems to be a common price. www.ebay.com.au/sch/i.html
Even cheaper for larger quantities...www.ebay.com.au/itm/Caravan-Hot-Water-Anodes-Anode-rods-suit-Suburban-HW-services-10-Pack/264420575098%3D1110006%26algo%3DHOMESPLICE.SIM%26ao%3D1%26asc%3D228419%26meid%3Daf53dfa1d2e24984b7db9c53d8421d6e%26pid%3D100005%26rk%3D8%26rkt%3D12%26mehot%3Dpf%26sd%3D153980807628%26itm%3D264420575098%26pmt%3D1%26noa%3D0%26pg%3D2047675%26algv%3DSimplAMLv5PairwiseWebWithBBEV2bDemotionHighArw&_trksid=p2047675.c100005.m1851
Cheers,
Peter