I cannot add much more than what Chazz has said, but have to disagree with you strongly on it being expeensice - quite the opposite. Companies such AE and Losi sell their screws/fasteners for between £2.25/3.69 per pack, where as the X-Factory ones at just £1.29 are exaclty the same at almost half the price in most cases and much more than half in many more packets......
We then take the most popular sizes amd already VERY good value fasteners, put a selection of 18 of the most popular sizes (multiple packets worth of some sizes too) into the package (over £27 worth at normal "cheap" retail) plus of course the X-Factory logo parts box (UK RRP £7.99), giving over 150 pieces and it then sells for less than £20 (which is more than £15 less than buying them loose - even at our cheap everyday prices), from Losi for the same money you would get approx 90 fasteners and no box!!!
So......YES I do think it is cheap!