Considering leaving the army.....

Hey y'all. My husband has been considering leaving the army and going reserve for a while now! His window is open and he is about to start the paperwork for terminal leave but he just found out that he is being considered for a promotion that he has been waiting for and now he may be changing his mind.

Does anyone have any advice on how I can help him make this decision? I know things will be different and any infertility specialist or treatments will be expensive if he gets out but he was so sure that it's what he wanted to do before the possibility of this promotion! :/