PabloLito

Hi everyone, I hope all of you and your budgies are well and safe. I need your help! My budgie ‘Lito’ has developed a lump on his lower back, I have no idea what is it. He has plucked all the father around the area and biting it constantly. I have done some research on internet but couldn’t really found an answer to it. The only recurring information that I have found is that if I take him to a vet there is high chance that he could (if surgery is required). I am rather have him for few more months than Combe home without him after visit the vet. Which has all of you know won’t be cheap either. I really don’t know what to do, I hope someone here knows more about this lump. Photo attached.