"I don't have anything to wear"

And I thought just girls used this excuse.  I actually heard it come out of my sons mouth this morning.  Actually what he said was "I have worn all my clothes already this week."  What he means is that right now he really only has a couple pairs of pants that fit him and he has worn them this week and therefore he has nothing to wear.
These battles are normal and they are exhausting.  I really don't care if you only have two pairs of pants, get up and put them on and get your ass ready for school.  He then commented on being a dirtbag for wearing the pants again.  I told him that jeans are jeans and no one really cares if you wear them more than once in the same week.  I an constantly doing laundry and so lately all of our clothes have been clean and so it is not like he is digging them out of the dirty clothes.
I choose not to fight with the kids and I try not to yell and scream because I have learned that it does not accomplish anything.  
What he doesn't get is that right now I need to curb my spending and focus on a few things that are more important that new clothes.  He knows that I love to shop and if I could, I would run out and buy him all the things he wants.  He on the other hand does not believe me and thinks that for whatever reason, I don't go out and buy him the clothes and things that he needs.  
I am tired of fighting with him and I just want him to wake up one day and whipe the asshole out of his eyes and go back to being the sweet and loving kid he was just less than a year ago.  I lay awake some nights trying to figure out how to bring him back to reality and I just don't know how.
What I have learned is that every morning there will be an excuse and I just need to stay strong and over come that excuse with him and get him moving.  The drawback is that it sets his mood on super asshole for the day and then I have to deal with that.