If the
plant is yours, have you considered sitting a rock on a longer shoot to hold it to the ground till it roots? Then clip it loose from the original
plant and dig up. (I know it works well for lots of other
plants.) I just bought my first dwarf purple barberry for our foundation plantings... they are so pretty and eyecatching... but sooo expensive! So I have 2 dwarf youpon hollies then a dwarf purple barberry in sequence across the front of our house (90 ft). It actually looks nice, but sure couldn't afford to do all barberry across the front... the hollies make the barberry leaves stand out nicely.