Have you tried putting up a notice on a noticeboard in the canteen/SU of colleges that do media courses like DIT aungier ST, DCU, Griffith, Ballyfermot etc? I know it's not the ideal time of year, but you might get lucky and have a 3rd/4th year who no longer needs it but didn't think of selling it on yet?
I wouldnt hold out on getting this book second hand. I see it is out of stock on amazon. I would think any law student that bought this book they would keep it as a reference book. I see it is for sale on a americian website for $154.58 but I think that would be close enough to €120.00.