I'll also recommend Jerry Freeman's whistles. He's one of the most respected people in the whistle community, and he stands behind them famously.
What Jerry does is take cheap whistles (like Generations), and tweaks them to make them play easier/better. The Mellow Dog is actually the combination of one maker's head (still Feadog?), and a Walton ("Mellow D") body - unless things have changed. He's made some improvements in recent years. Here's a link to a post with sound clips: Jerry Freeman's whistle clips
. I have no affiliation with Jerry, and if I'm breaking any rules by posting that link, feel free to remove it.
I have one of his Mellow Dogs, and it's a great whistle. I would recommend spending the extra $5.00 (unless it's changed) for the C body. I think that's still less than $50.
I also have a Parks Every Whistle (mentioned earlier). It's also a very nice whistle (PVC), and has the volume control on it, but I think it's slightly out of your price range.
As far as Erik's whistles; unless things have changed, he just tunes a bamboo body and attached as Susato head. I don't have one, but I rarely see them discussed on the whistle forum (chiff and fipple).
I'd bet that most people in the whistle community would recommend Jerry Freeman over Erik. It's like the NAF's that Erik makes. They're probably fine, but you might be happier with a maker who focuses more on the NAF, rather than Erik, who makes several different types of flutes. Same with the whistle.
I don't have a whistle by Erik, so I can't speak from personal experience there. I'm just sharing my thoughts after spending lots of time being active on the whistle forum over the last 5-6 years.
Whistles can take some time to get used to. They're not quite as easy to play as the NAF. It's very common for new players to get a lot of squeaks and squawks, and think something is wrong with the whistle. It just takes practice and a generally light touch with the air.
Hope that helps!