It costs public sector depts and orgs a huge amount of time and money to run even the simplest of procurements under these regs. The cost in papaer alone can be staggering if there is a large tender document (stationery and "office" products springs to mind) that have to be sent out to a large number of prospective suppliers.
I did a tender for one central gov dept that was in the very early days of e-procurement. Not many potential bidders you might think – well think again, there were over 60 and that was through the restricted procedure, there would have been even more and I would ahve been totally swamped if it had been through the open procedure. It took 6 months to run the competition, which was then effectively obsolete from the inplementation date as the dept then went on to buy a full ERP solution that included a full e-procurement and e-catalogue solution! Better planning would also have helped avoid the probelems of duplication and the costs associated with it.
Raising the threshold and combining it in a formula with the risk factors associtated with the importance of the project to the dept / org would allow higher value / lower risk projects to be bought without the need for the current lenghty process and esure that high risk projects are captured.