How many IUIs before you decided to move to IVF?

Andrea
Woke up this morning feeling AF coming on. 3rd IUI failed. Dr said it's normal to take a few rounds to work. But how many before enough is enough? I'm not ready emotionally nor financially to move on to IVF. But I don't know how many more failed IUIs I can take either. I just don't want you give up too soon eother.