While wandering my local 99 Cent Only store, I came across a small section of clearance items (mostly easter stuff) and found these stickers for only 25 cents! Not all stores may have these or at this price, but it's worth checking out.
Sticko - Camp Stickers - 18 pieces
Sticko - Las Vegas Stickers - 18 pieces
Sticko - Sports Stickers - 47 pieces
Sticko - Artist Stickers - 26 pieces
Disney Toy Story Stickers - 4 sheets