Golan Telecom announced a new deal today for those switching to Golan Telecom and keeping their existing numbers. For the first six months, the unlimited plan will cost only 49 shekels per month; after, the cost will revert to 99 shekel per month. New subscribers wishing to obtain a new number (with a 058 prefix) will pay the standard 99 shekel.
This deal is valid from today until (and including) January 21, 2013. This includes activating the SIM by that date.
So far, details are only available in Hebrew, and can be found here.