Add little splashes of warm colors for fall and Thanksgiving decorating on a budget. Little things like fall trivets, magnets, and coasters can add a festive touch without breaking the bank.
So... go small! Just invest in a few inexpensive items with, say a fall or Thanksgiving theme on them. You can then add a few more next year. If you choose items in warm fall colors, you needen't even get things specifically for Thanksgiving, which you'd only use for a few days.