I used to work in professional theatre doing costume construction, so I put alot of effort into my costumes. However, I am also a major bargain shopper. So I will usually spend $100-$150for the materials for my costume, but without my ultra-thriftiness, it would've cost about $200-$300. I really enjoy the experience of making the costume, so for me, the cost is not only for the costume, but the hobby of constructing clothing. Ends up being alot cheaper than going out all the time.
This is the same for me. Costume creation is a big hobby of mine and has been since I was first put on costume crew in 9th grade for a high school theater production. I'm typically very pious about everything I buy, but costumes can become my exception. I usually haunt thrift-stores and the like, but if I find something that I
know will make the costume extraordinary (and that I know I will regret not buying later) then I'll splurge. Also, I like to get involved with events year round that involve costumes, so I usually end up getting a lot of mileage out of whatever I make.
For instance, I bought a high-quality wicked witch of the west costume two years ago for Halloween that cost $120. I wore it to host my party that year, to take my niece trick or treating (except I morphed it into Lizzy Borden), to Dickens on the Strand in Galveston, Texas, and finally, this Halloween one of my cousins borrowed it to be the Wicked Witch again. Because its a simple, black, Victorian dress, I can pretty much alter it to be anything within those bounds. So, I would say that was a solid investment.