It’s been a long time since I had a wooden whistle. The other day I tried an Abell and loved it. His are going for $450 now. But I was wondering if there any good wooden (high d) whistles in the less than $300 range? I tend to over blow because I usually play flute.
Get a Bleazey whistle, powerful tone and needing a good push. £145 for a D.
Abell whistle is good and OzWhistle is too. Oz Prices are Australian $ which might bring it into your price range depending on exchange rates. Different woods to choose from also.
Tommy Dion still offers ‘‘Whistles of Wood’’ CP Woodwhistle pvc copper prototype makers tip moving holes tunable for $150.00. I enjoy playing several of them.
I have a Busman D that I paid $260 with shipping. I find it takes a bit more breath than, say, my Harper, which has a higher back pressure with it, so you might have better luck with it. His site is http://www.busmanwhistles.com, and he’s on here, too.
I’ll be listing some of mine in the next few days, $50-75.
i’ll be looking!
You could try www.theflutemaker.com. They are whistles.
I have a lovely bamboo C whistle that needed only a slight tweak for intonation. It cost me $1. 
Sometimes you can find bins of these at fairs and festivals and pick out a good one. I’m on the lookout for a D …
have look at mine - www.westonwhistles.co.uk - all under £100 depending on your choice of wood
Jetboy
You might also want to check out Gene Milligan; he made a beautiful tuneable with all black delrin head joint and red dymondwood body with brass fittings for me, and the price is below your stated limits.
Philo
Thanks, there a lot more options then I thought. Which of these can you really lean into without overblowing?
Thumbs up here for chas’s whistles. Everyone who has seen mine asks if it is a Weasel. I did a quick review herehttps://forums.chiffandfipple.com/t/whistle-review/70691/1 of a rosewood one. Pix are not that great., but I love the whistle. Worth the price of admission at this point for sure.
A wooden whistle you can lean into without overblowing, and one that won’t break the bank either, would be one from Sweetheart.