I know it’s a bit late for this year but you might want to order for next year. These are really cool – a set of 4 flameless tea lights with the Advent colors for only $7.50 (and actually now selling at 20% off or $6.00!) at Church Supply Warehouse.
And, if you’re looking for a comparably low cost (small size) advent wreath (12 in), check this one out from Consumer Crafts, now only $3.97. Liturgical environment for your classroom (or home) on a shoestring!