To be fair to MO'L, the £50 fee is to deter time-wasters from applying. In a previous life, I was part of a team given responsibility for sorting out applicants resulting from a series of ads we had in FI. We received over 10,000 applications and sent out plenty of documentation (at around a fiver a pack), but I reckon a good 95% of those were either not returned or returned by completely unsuitable people just chancing it despite what it said in the ad and again in the pack. Out of the 100 or so viable people we ended up giving 7 jobs if my memory serves me right.
If we had charged £50 'processing fee' you can bet your bottom dollar that the vast majority of the 9,500 timewasters wouldn't have applied ... and those that did would have covered the expenses of doing so.