I'm looking to cosplay Valentine from Skullgirls at May Expo this year, but I'm having trouble finding a wig for her. I can't really afford to commission and lack styling expertise myself.

References:
http://www.xbox-360.co.za/wp-content/uploads/2012/02/skullgirls_valentine_slash_copy.jpg
http://quartercircleback.files.wordpress.com/2011/11/valentine_syringeload.png
http://gamegeex.blogomancer.com/files/gamegeex/images/Fighting%20Titles/Skullgirls/skullgirls_valentine.jpg
http://mature-gaming.com/wp-content/uploads/2012/02/skullgirls-valentine.jpg

I had a look around myself, and have found that wigs for Nezumi from NO. 6 are fairly close in style, but they are a much duller blue., while Valentine's hair is a more electric blue http://www.ebay.com/itm/New-Nezumi-Future-City-No-6-Short-Ponytail-Anime-Cosplay-Party-Hair-Full-wig-/260881581740?pt=US_Costume_Accessories&hash=item3cbdc106ac

I've also considered dying my own hair for it, but the last time I did that for a costume, it really didn't turn out well.

If anyone has any advice for me, that would be fantastic - thank you!

Found these, they're not exact so you'd probably have to style/cut the wigs.

http://www.ebay.co.uk/itm/Hakuouki-Heisuke-Todo-Cosplay-Short-Dark-Blue-Hair-Wig-Ponytail-/150726042842#vi-content

http://www.ebay.com/itm/New-Future-City-NO-6-Nezumi-Blue-Gray-Piagtail-Cosplay-Costume-Wig-Free-Wig-Cap-/221119525788?pt=US_CSA_MWA_Wigs_Extensions&hash=item337bc0339c

http://www.ebay.co.uk/itm/Panty-Stocking-Kneesocks-Clip-Ponytail-Cosplay-WIG-/170714953331#vi-content

http://www.ebay.co.uk/itm/Optional-Pony-Tail-Clips-Swag-Pixie-Bob-Wig-Women-Adult-A1989LA-/360516857136#vi-content (really light but it could work if you only used one ponytail)

http://www.aliexpress.com/item/C3-C-Cube-Ueno-Kirika-1755-Deep-blue-a-ponytail-long-cosplay-costume-wigs-free-shipping/570296323.html

I guess if you really can't find anything, if you're good at styling wigs with (or even with wig glue) then you could try just a short/medium length wig, make a tiny ponytail and spike/fluff it up to look like hers?
I'm not very good at wig styling so I can't help you there =(

http://24.media.tumblr.com/tumblr_m9rf0uRYcX1qjbnv3o1_1280.jpg

seems like a short wig with a clip on ponytail, you could message some ebay sellers and ask them. I know i've messaged about changing the colour of a wig once and they were fine with it for no extra cost so you could always try that too =3

http://25.media.tumblr.com/tumblr_m98v1mLx0m1raa3n8o1_1280.jpg

looks like they just spiked the back up of a short wig aswell ^^

Thanks so much for all of that, its really helpful to see all these links and stuff, hopefully this goes to plan!