The thing to watch out for with the student-grade art supplies is the same reason shelling out for the good stuff is worth it. Student grade stuff doesn't contain much pigment; it's mostly fillers and binders. They can go on grainy and uneven, and tend to look dirty. The acrylics, I haven't used the cheapest stuff before, but I did use the Liquitex Basics before I upgraded to Golden Fluid Acrylics, and I will say the difference was phenomenal, both in how they applied, and how easy they were to thin out to the right consistency; makes me glad I never bothered with the cheap stuff. I used to be a very strong proponent of the whole "it's not about the materials, it's about how you use them" theory, but now that I've upgraded my supplies, I can get even better results. Yes, it IS possible to do good work with low-end materials, and no, good materials do NOT mean you can automatically get good results. Art supplies is almost exclusively a 'you get what you pay for' deal.
A few things I will recommend in general from both ends of the spectrum. Crayola watercolor palette.
This is the set I've been using. You can get the 16-color set for $5 at a Michael's, cheaper if you have a coupon. Another thing is the Blick brand Artist Soft Pastels.
Sets are available; go for the portrait one if you want a good line-up of blushing colors, and one of the assorted sets if you want a range of other pigments. They also sell open stock, where you can buy individual colors, and they carry the Pearl Ex shimmer pigments if you want to use some sparkles.
Crayola Watercolor Pencils are fine, but you will encounter the same problem with mixing colors. My advice to you would be to locate your nearest craft super stores (JoAnn's, Michaels, Hobby Lobby, AC Moore) and gather up their coupons. JoAnns and Michaels accept competitors coupons, Hobby Lobby does not, and I have no idea about AC Moore, but you can wait til one of them puts out a 50% coupon, print it out a few times, and take one copy to each store that accepts them. Use one to get a good set of pastels, another to get a good set of paints.