'Try getting a quote from these guys,Ive been using them for the past few years 3-4x a year, no one has matched them or were cheaper, if you do please let me know if they beat what you have;
http://www.noachcar.co.il/
I too have been using them for years--multiple rentals coming to 50-60 days a year. They rent via Hertz, Budget and Shlomo Sixt. I would strongly strongly strongly suggest you use either Hertz or Budget. The complaints about Shlomo Sixt are more significantly numerous than other Israeli rental agencies.