I'm hoping to write a review of these, as soon as I have time, but I bought one of the new ones from the Sennheiser/Adidas line - OCX 685i. Before I go into any details, they're above your price range since they're $80. I have also used the Bose ie2 and Soundmagic E30 and a few others that didn't work. Personally I prefer to use something with a cable I can wear behind my neck and down my back - especially if I'm moving around/working out so they don't get caught.
Few things here: I have an iPod Nano 6th gen, I run 18-20 miles a week outside, use the elliptical and do weights and this is truly the first pair of headphones (iems) I've bought specifically for working out that do not budge once I get moving. My first concern for workout headphones is that they stay in and my second is sound. These are extremely comfortable, do not budge during workouts and the control works extremely well - even on the move. My minor complaint is that, although I never used the older version, I wish they had kept the short cord/extension cord option. Granted when I wear these with the cord behind my neck and down my back, the cord isn't a problem. I tend to pull the cord up just enough so the remote is still by my collar in front/accessible or I weave them in such a way that I have access to the controls. I really like the sound on these and think they have a good amount of detail and bass - without the bass being overwhelming. I may be wrong but I think this might be the only one in the new lineup that has iphone controls.
I've had these a short time but the biggest test was the 10k I ran last week and they didn't budge once and I didn't even feel a need to mess with them. I've used them on a few short runs and on the elliptical as well and love them. If I don't like it - I return it. It's that simple. The thought hasn't even crossed my mind since the first time I tried these out.
** If you want to know what other iems I own, check my profile. Oh and since I liked the sound on the Soundmagic's so much (until a sudden downpour killed one ear) I was debating trying their sport line but I didn't get around to it. I believe they are $60 with the ipod controls. I don't know if they sound anything like the E30 but if they do - that would be a win/win. It's just another option I know of.