I wouldn't let the vet bully you into it personally - I have only ever had two of mine tested, and both times because of illness (Well, Pebbles was done before she came, vet wouldn't let her go to a home unless it was done, she was convinced there was something wrong with her even then!!), Tiger was done after having had contact with the others, but it was never suggested to have the others done. The main prob you will have is if it turns out to be something like FIP, as there is no conclusive test for it, so you will know the FIV/FeLV status of yours, but if it isn't that, you haven't really gained much. As she had little contact, FIV is incredibly unlikely, but FeLV is easier to transmit. I agree with asking prices too, teh rescues vet fobbed me off with prices, and it cost me £60 for the Glasgow test - it is £34 at my own vet!!