Are they really that cheap? You need a calliper and rotor, lever and really a linear slic cable.
Just very quickly from CRC (I know you might be able to get bits from elsewhere cheaper, but this was for a quick easy example):
Linear slic cable £9.99
Avid BB7 Front 160mm rotor £39.99
Avid FR5 Lever £9.99
Total: £59.97
Fine if you're getting it all second hand as it'll be a bit cheaper (although i'd fit new cables at least) and even then it won't be much cheaper than that hope at £60.