Cost of the Disengagement Plan:

Because of the complexity of the Plan, it is difficult to pinpoint a precise figure, such that it is better to speak of a range of potential cost. Israel's Finance Ministry initially issued an estimate of 5 milliard* shekels (US$1.15 milliard), as part of Israel's approved National Budget for 2005, which was when civilian compensation was fixed at 3 milliard shekels; on February 16th, this was amended to 4.3 milliard. Other government ministerial figures bring this to the 7 milliard shekels range (US$700 million to US$1.6 milliard). [Unofficial estimates range beyond 10 milliard shekels (US$2.3 milliard).]

Estimates are based primarily on the cost of physically evacuating and compensating Israeli civilians being transferred - for their homes, property, and businesses - with no figure for government-promoted housing, or business / employment initiatives.
The Compensation Law increased the initial official figure given by the Finance Ministry, in response to calls for a fairer package - and raising the figure. In the end, the Budget for 2005 (March 2005) phased the costs through into succeeding years, so the final estimate of costs is still unclear.

In addition, there is the cost of relocating military facilities, infrastructure, and crossing points outside the Gaza Strip and Northern Samaria. Data on military costs were not available, but comprise part of the Defense budget.

Notes
*Milliard
For the sake of clarity, Israel adopts European numeration and we have used it here:
Milliard =One thousand million;
Billion= One million million.