NuForce BE6i are my go to wireless IEMs
7hour battery life or so, charge is a little slow, but uses a standard micro usb. aptX bluetooth too which is good. IPX5 as well, so copes with moisture. Really nice Comply foam tips, but comes with others and some odd wing attanchments. Seem them down as low as £45, so not hugely cheap. But cheap enough that I don't worry about them.