Would strongly recommend considering cheap-ish IEMs and whatever 3.5 - USB suits your phone. Will open options a lot. MAYBE a little fund creepage (but only say... £30).
The Tangzu Wan'er can be had for £13 + postage at the minute, not the cutest looking but will utterly destroy anything else (except other well priced "chi-fi") remotely in the price range on sound quality, the cables usually about £3 and postage... maybe IS doable in £20.