My first hand-made whistle which I've had about three weeks (the cream-coloured one). It's a Parks Every D (No. 683). Yes, it might be made from PVC piping, but it sounds great* and has the bonus of an adjustable window 'ring' which allows for ultra-quiet, if somewhat unpleasing-sounding, practice. It cost me around £40 inc. post and packaging from Big Whistle Music.
My old whistle (the black one) is a Clarke Sweetone D. I think I remember paying around £5 for it. I've had it ten years or more, but sadly put it down after a few months as I got frustrated with not knowing or liking many of the simpler tunes in book I brought. One of the brilliant things about the internet, and sites such as YouTube, is that it has opened up a world of songs. Just try and stop me now!
*Unfortunately I've begun to find that after around 20mins playing it begins to 'buzz' and miss-note. I think this is due to the main body of the pipe over-heating. I find I can mostly overcome it by 'opening' the window a bit and shortening the overall length of the pipe through the length adjuster (yes, it has this) but it's still frustrating.