A.H.
My vote is for books. Always. You can get books at all sorts of prices for all ages. Sometimes my grocery store has them on half price. Sam's Club is a good place to buy several books and keep a stock, things like Dr.Seuss or Golden books. Bookstores often have discount books in their children's sections.
The biggest hit at the last birthday party I was at was a little foam bunny that grew in water and shrank when you took it out. It was about 2 bucks.
Hot Wheels are less than a dollar a piece at Wal-Mart. Four of these are fabulous.
And kids? The more separate things wrapped, the better, so wrap each hot wheel or book individually. The stack of gifts tied neatly with a bow will drop any kid's jaw.
If kids get too much from one person, the tend to forget everything that person got them. On the other hand, one really special thing will stick with them forever.
I have a 3 birthdays immediately following Christmas. That's tough, and I've seen my strategies work pretty well.
Good luck!
** I've also been thinking about ideas for your daughter: If there is something you personally are going to do for/give to her, you can supplement that with the party. For instance: my daughter wanted to grow her library. She threw a Book party. Everyone who came brought at least one book, coloring, handmade, or store bought. If you think she's ready for a pet, wants to go camping, or whatever, throw her a Dog party (dog pet supplies requested) or Camping party (camping gear requested). Or even :Scrapbooking gear requested! and let her go to town making a scrapbook for the next birthday kid.