I don't think it's silly. I have purchased a few things that were a bit too small because I found them at a super awesome price (and I'm petite so the right proportion is important!). I was a size 18 and am down to a 14.
I am planning on splurging on a whole new wardrobe if I meet my goal weight. I think that will be about a size 6/8; not sure because I haven't been that weight since I was a teenager.
I have about 31 pounds left to loose. I will allow myself $1000 of new clothes if I can get there. Husband said he will pay extra for all new lingerie.
Clothes are great motivation! Good luck!