Make sure you're comparing like with like when checking prices.
E.g. There are two usual UK packages around
010-00555-21: 705 + HRM (base)
010-00555-31: 705 + HRM + Speed/Cadence Sensor (+£30)
Sometimes bundled with Maps
705 + HRM + Speed/Cadence Sensor + City Nav NT 2010 UK (+£60)
705 + HRM + Speed/Cadence Sensor + City Nav NT 2010 Europe (+£100)
Note:
Product numbers NOT ending 21/31 are imports. (20/30 are from the US).
Shaun