hey-- I remember being in that spot (feels so long ago, haha...I uh, now have a medium sized rolling SUITCASE to hold all of my stuff for photoshoots/makeup gigs, lol) so I'd suggest checking out:
Caboodles: They make more than glittery plastic cases for preteens now-- they actually have some pretty decent metal traincases with fold out trays, some of them even lock. I've seen the best selection at Target, my roommate (Fashion Design major) has a few of the smaller ones to organize her vintage jewelry and they put up with a lot of abuse as she isn't too nice to her stuff. They don't look little-kiddy at all so I'd look around for them.
Yazmo.com: Disclaimer here: I can't speak to the quality of these cases as I've heard mixed reviews. Some people mentioned that the movable dividers were actually just very thick coated cardboard rather than plastic like Sephora's cases. However, if you aren't planning on traveling with it too much and aren't like my roommate (ie: very abusive to belongings), then they might be good starter cases for you. One thing they *totally* have going for them is all of the fantastic, fun colors and finishes-- pink faux croc/red patent/translucent colors/clear/regular aluminum, etc. they even have orange for heaven's sake
Makeup Cases | Cosmetic Cases | Train Cases - Makeup Cases
ebay: You're chancing the quality here again, but look hard at the seller's feedback if they sell a lot of cases and you can usually get a decent idea of what you'll be getting. *Do Not* pay more for a "brand name--authentic!!!" case as there are a lot of fakes out there-- decent ones, but not worth paying for the name when you don't need to.
tackle/toolbox: if you can give up the idea of having a slick traincase-- I'd bet serious money that you could find a case in the hardware/fishing isles of sporting goods places or big box stores like walmart that would fit your needs-- and be $30 or less. Some of my first makeup cases were Plano tackle boxes and they were quite perfect for me for a long time. If the (sometimes) ugly colors put you off then you could always make it a project and get yourself some gorgeous outdoor spraypaint and painter's tape and go at it
whew! sorry that I'm always so wordy!
hope to see you post pics when you work out what you want,
meg
edited to add: you could also always wait until Sephora friends and family (F&F) discount in November. It's usually 20% and would earn you free shipping too. The girls on the makeupalley.com makeup board are fantastic about keeping up with the codes.