+/- 1
You can get a SB for about £30 cheaper than an IB at the moment.
For a good overclock (if that's what you want to do), you'll also get away with a cheaper cooler if you go for SB rather than IB. What you won't get is PCIE 3.0, or the faster in built graphics. For me, PCIE 3.0 will probably not be required for at least a couple of years. The on board graphics won't be used (when I finally get my GTX460 sorted). Therefore, for me, the choice between IB & SB was not so clear cut, and in the end I went for SB. Saved at least £50 and ended up with a fast,quiet PC, and more of a known quantity in terms of what it can do and reliability.
Obviously, many here will advise IB, and I really wouldn't say that's bad advice. However, to dismiss SB at this stage might not be so wise (for some).