I can relate. I had been planning for surgery for almost 3 years, so decided not to buy any new clothes. Believe me, after 3 years the closet was looking pretty ragged and I couldn't stand it anymore. I started by replacing some underwear and bras and that made me feel a whole lot better. When I started losing I replaced a few items and it felt so good to have something new in a size that actually fit. I'm not buying much, because I'm not at my goal weight, but right now all the size 22s and 20s are gone and I have enough 16 and 18s to get me through a week of work. Some clothes don't look bad if they're a little bit big, but there's a point where you look like a gangsta with pants falling around the knees.
Recently I had to get out a fancy outfit to go to a Christmas party, put the skirt on that I wore to the last one, and it fell to the floor. Ha! What a rush! But it was an expensive piece of clothing that I wasn't going to replace and wear for just a few hours, so I got out some elastic and put it inside the band. It worked and the skirt didn't fall off!
I've also heard that your shoe size can decrease with weight loss, so don't load up on a bunch of new shoes just in case.