Please suggest me the Low Whistles you like best in key of D,G and C.
And What’s the normal price of Low whistles in key of D,G and C?
Do high-end whistles sound better than pennywhistles?
Warren
Warren, you really know how to stir up a hornets nest.
My favourites. In D, Overton and Copeland, in G, Overton and Burke and my only low C is a Howard which I like well enough.
That depends on the brand. You can pay about $800 for a Copeland silver low D and is little as $50 for Dixons and Susatos or anything in between depending on what you want or can afford. Note, I haven’t checked the prices I gave you recently, I’m just giving rough estimates from memory. The important thing is to either figure out your favourites and then check prices on websites or figure out your price limit and then find out what is available for that price.
There’s a huge difference of opinion on this question as regards high whistles. Some would say yes, unquestionably, others no, unquestionably. I would say that there isn’t a close correlation between price and quality. IMO, some expensive whistles aren’t worth what they cost, others are bargains. Some are very consistent, others seem quite inconsistent. A good Generation or Clarke is a very good whistle despite its cheapness, a ‘bad’ Generation would be nearly unplayable by me but not necessarily by someone with decades of experience although even the best whistlers are divided on this question.
As far as low whistles go, I have not heard anyone say that the relatively cheap (Susato, Dixon) are better than the relatively expensive (Burke, Copeland, Grinter, Overton). Don’t read too much into this though. My impression is that some of the people who champion cheap high whistles simply don’t like low whistles at all and would recommend that you learn flute instead. But, then again, I doubt that any of the people who don’t like low whistles would prefer cheap flutes to expensive flutes.
Low whistles?
Favourite metal low D’s : Copeland, and my Alba “broken arrow”
Wood: Yvon Le Coant
Low Eb, metal : the new redesigned Chieftain. But I may give a try to a Reyburn someday. I strongly regret there’s no Copealnd in that jazz tone…
Wood: none I know of 
Low G : Yvon Le Coant, by all means, and it’s (kings)wood.
Metal G: This Reyburn is nice, as second best after above.
Might check the main website, where many of these
whistles are reviewed. Best
Low G…Overton
Low D…Copeland brass
Low C…Alba Q1 (plays soft and loud)
Trisha
I love my Alba low D! I will miss it when it’s gone after the raffle, but it is far and away my favorite for volume and voicing! (I’ll probably buy another one…) 
Bill Whedon
My current favorite is an Overton Low D. I have an Alba Low D temporarily that coud give it a run for the money if I could get more time with it.
You can get a pretty decent Low D for $18 from Jubilee Music ( http://jubileeinstruments.messianic-webhosting.com/jubilee.htm ). We had three of these whistles at our SF Low Whistle fest yesterday. Keep an eye out for reviews from Lumihead (the raffle winner), stiofan (the hosta), and myself (the organizer). We had several of the people in attendance fill out a rating sheet on these and other low whistles as well. Once I compile the data I will post it here for all to see. In general though, the Practice whistle was well received.
Hello Warren!
I like my Low G & D Hoover whistles. 
As for the high ones I like my Clarke, Generation & Sweetone whistles.
Best of luck in your whistle search !!
Just noticed I replied–as too often 
--not exactly on topic:
asked what low C, D, G I prefer, I replied by a D, G awright and for some reason Eb…
For a low C, I’ll have to chime in a vote for that superb Alba (not Q1 type) tunable low C.
Just to drift OT 
it may get a Db tube for these Eb-minor jazz things.
I too have a tunable Alba low C (purchased after recommendations by Zub.- cheers!) and it’s an amazing horn-and very good value,to my mind.
I also enjoy my Copeland brass low ‘D’,and Bernard Overton low G.
I also have to put in a good word for my Colin Goldie Overton low ‘F’.
I have my hands (and arms,and shoulders,and right leg!) tied up with Uilleann Pipes now,but if I have a further attack of Whoa sometime this year,it might just be for an Alba low Bb!!!
Low D: Overton and Alba.
I like my Overton low D