Everything you are having done should be listed on the consent form or verbal consent can be obtained over the phone later. You do not have to pay for things you have not given consent for. I am very particular about this and if I handwritten things in on the printed form I ask the client to initial those hand written items so there is no dispute. I always offer and provide an estimate of costs and you are entitled to this. The vet should explain where costs might deviate from those such as a lump removal being more difficult than anticipated so take more time and more expensive. Please don't feel bad about asking for all of this it is not unreasonable and a good practice will happily do this.
vet's called today to check i had remembered our cats op' tomorrow and not to feed her after 10 (we hadn't..). i mentioned that we are very tight with money at the moment and that i wasn't sure if our pet insurance would refund so could she please ask the vet to do 'add the odd thing in' (as i don't trust them). she went over what he was going to do which included an additional blood test that he hadn't told me he was going to do and i don't think necessary, she had had one done (same) a year ago and was clear. i know some vets add things to make more money, i view them with suspition same as car mechanics. someone in my family is a vet and i remember in the past being shocked by some of the things he had said, possibly lying (showing off) or just plain old dishonest but has made me very wary. (i have attached some photographs for those of you who like to see other cat members pictures, she is big fluff ball)