A 70L dry cabinet will probably set you back around $200. Check with shops though.
Unless you are very particular about the humidity inside the dry cabinet affecting your equipment, an analogue one will do. One with a digital hygrometer (not sure how can the dehumidifing unit be a "digital" one) will cost another $30-$50 but is very accurate in detecting the humidity within.
I'm using an analogue one and so far no problems at all.