The meter I linked above mentions 10 kHz, but can't even DSO138 work with faster signals? Okay, it's not a multimeter... but it is small, cheap, and can work on batteries (I guess). It didn't get too many shining reviews (at least the ones I've seen). Getting the unsoldered version is riskier, as it would be hard to be absolutely sure or prove that there wasn't an issue with soldering the kit together if something doesn't work.