weird thing in store

i dont know if its only for me but suddenly when i open steam on chrome browser the prices are in £ and when i check steam and retart it its still in $ also when i check it in mozilla its in $.
also the prices arent right(for example rage in steam its 30$ and in chrome its 30£ and mass effect 2 on steam is 50$ and in chorme its 15£)
also i am missing dead rising on steam and i got it only in chrome.
does somebody know what it means and which prices are right.
thanks