Hi,
I looked at these and asked the same question you have and the feedback was the best way was a genuine Audi armrest as it fits perfectly, is robust and matches the rest of the trim in the car. After a few calls checking prices I managed to get a deal from my local Audi dealer. Fitting it myself was easy as I followed the instructions from an A1 forum member. One thought though, if you aren’t going to keep the car for a long time, then the eBay one will do the job.