I would agree with Michael in that there isn't much point in doing the vet check again unless there is anything that makes you suspect something is wrong during the quarantine but I would also base that decision on what the initial vet check involves, if its just a quick physical check then it may be something you wish to persue to go more in depth.
The other option is just submitting a few feceal samples as this is completely non invasive to the bird. Alot of virus, bacteria and parasites can be tested through the poop samples though may not be as accurate in some cases. Poop tests also seem to be cheaper than bloods though tbh I've not found any of the basic testing to be as expensive as I thought it would be as a one off, although it does start adding up when you put all the tests my two have had together but that does depend on where you go. Obviously financial availabity is different for different people, just in case you are interested my two have had, 1 x-ray, 4 seperate lots of medicines, 2 lots of nutritional support powders, 2 blood draws, 3 sets of feceal tests, 1 lot of pro-biotics, 3x basic physical feather analysis, 1x day boarding, not to mention the consulation fees and all that has come to under £300. The latest bill was £20 something for consultation, 1x feceal testing and a 3ml bottle of metacam so it needn't be too expensive if it helps set your mind at rest. It is completely up to you, the only thing I would urge you to do is to be really strict with your quarantine procedure
