I think the
Hifiman RE-400 is just the IEM that you're looking for. I've managed to try it at a local headphone store and it's pretty amazing for just $100. Compared to the gr07 MK II ($170ish on ebay), the sound signature is almost identical, with the re-400 having slightly more bass. That being said, the gr07s are a well balanced IEM. They're not neutral, but they definitely don't have overwhelming bass or treble, likewise with the Re-400. The Gr07s though are a bit better in dynamics and technicalities, and the cable can be worn over the ear, so it tends to make less cable noise and is less likely to fall out. They both don't have detachable cables but detachable cables are a premium and you wont find them till around $300+ (edit: I guess there are some exceptions to this) (Edit 2: What i mean by this is that the $300+ detachable cables use the Westone style, which is fairly universal and used for most custom IEMs.)
For more info on the re-400, check out
Clieos' review on it. The Re-400 will be one of the best choices for a balanced sound signature at $100, plus you'll get amazon prime shipping and easy returns on them (Edit 3: Nevermind, you're in france, but this will apply to those in the US). If you can get a good used price on the gr07s though, I would get it over the re-400.
The
Beyerdynamic XP2 is a good choice too, if you can find a place to purchase them (they're only available in Asia for some reason). If you want to look into more IEMs, I highly recommend taking a look at
Clieos's "list" for the best price/performance IEMs.
The
Shure SE215 is detachable but according to Clieos' review, it is a mid-centric IEM with more-than-neutral bass and treble that's present, but doesn't stand out.
I hope that helps!