Here's a review of the Aulos Baroque single-key plastic flutes by someone who' played them - Aulos Baroque Flutes. The dark model seems to be what you want, but the price is given as around $300. They are available online from several sources, eg Woodenflute.com or The Recorder Shop (The latter has it in soft case for $234.50, but that's about as cheap as I've seen; nothing under $100).