University Requiring GRE Results

Hi, I'm applying for an MSc Economics and the university states that applicants are 'expected' to provide GRE scores as part of the application. It doesn't sound like a hard requirement, so I emailed the department and was told that it is 'encouraged' and would strengthen my application. I don't know how to reconcile this, on one hand I really want to go to this particular university, on the other hand it is the only one asking for GRE results. If I was to take the GRE, I would spend hundreds of pounds and possibly hundreds of hours (probably a lot less) studying for it and I might still be rejected. I'm in my final year of undergraduate study, I don't know if I could even spare the time to prepare for it in the first place, but the fact that only one of my options is asking for it makes it hard to justify.
Any advice?