Bathroom- combine old separate toilet and bathroom

[MemoriesOfAnotherFuture]

I’m looking to buy a new house. One I’ve seen has a separate toilet and bathroom, which isn’t in itself a huge problem, but they’re both very small and a bit dated, though perfectly functional. They’re next to a large-ish bedroom. I was just wondering if anyone could give a ballpark figure of what it would cost to combine the toilet and bathroom and use part of the bedroom to create a new, bigger bathroom with new bath, toilet and sink?! I literally have no idea what sort of cost might be involved, so just wondering if anyone has any experience!