There are enough people out there who gladly pay 4,95 for a lithium coin cell. Just look what your local shops charge for these things.
Personally I don't have a problem with that, everybody's got to live somehow.
While the idea of reselling Farnell's stuff is probably not bad it doesn't really make sense to sell such standard items like coin cells. How would you decide what of Farnells products to sell? You can't really put all of Farnells catalog into ebay.
Standard parts - like coin cells - can be sourced much cheaper than Farnell offer them. They want 1,87EUR for 250+ qty. which is ridiculous - wholesale price for the same cell is about 0,50EUR for small quantities.