Ugh...I really dislike Halloween wigs on principal. Cheap fiber, none too much of it either, no skin top, bad netting, just generally awful quality. I don't even like styling them for other people. I'd almost rather ditch the yucky wig, buy a quality one myself and show it to them. "See, this is what a good wig looks like! It's really worth the extra ten bucks!"*
*sigh*
I'm picky like that. And it pays off. I've had people ask me frequently if the waist-length royal purple hair on my head is really my own. Which I can only conclude is because they've never seen a good wig before. I've had people in good wigs think my wig was my real hair. Maybe it's the skin top, I don't know.
So, yeah. I can see buying a Halloween wig for, you know, Halloween. I probably wouldn't myself because I wear all my costumes multiple times and I want something I can get mileage out of. But to stock up for the rest of the year...no. Not even for extra fiber to make wefts.
I have the same standards when it comes to bagged costumes. For what they charge for something like Vash's duster at a costume store, I could buy all the fabric needed for his outfit and put together a version that's at least as good, and is custom-fitted. My reaction's the same as with the wigs: ew~! Bad fabric, terrible stitching, and designs and details that are printed on. I know not everyone has the skills to make their costumes from scratch, but that doesn't mean I have to like the crap they overcharge consumers for. The Yugi costume I keep seeing at Party City makes me want to cry.
Now, other stuff, I will buy this time of year. It's a good time to stock up on spirit gum, since they start selling it at the party stores near my house. Small props like fake glasses, ear tips, gloves, little things that I just can't make myself or don't want to go to the trouble of making, I'll pick up at the temporary Halloween store near the mall. (Tights and stockings are another example.) But since there's a large year-round costume store within reasonable driving distance of where I live, I'm not too limited even during the spring and summer. There just might be better deals around now.
I do need to hit up the fabric store, though. One of my costumes requires some lavender vinyl, and you cannot get that in stores except right around Halloween when they have the costume fabrics in. I could order online, but the stuff they sell is of sufficient quality that I'll go the cheap route and buy it at Joann.
*Okay, so when I do actually buy my own wigs, they cost more. Sometimes a lot more. If you want quality, you have to pay for it, and frankly, it's worth it in the long run. I'd rather pay $45 for a wig that I can actually style and that will last me years if I take care of it, and that I have the possibility of selling later, than pay only $10 now and have it turn into a nasty mess after a couple wearings, if not right out of the bag. But that's just me.