WTP, how about asking your IT people about Skype?
Maybe there is a way to get an SMS on Skype instead?
At least for texting a cell phone from your end, there is a SMS charge of 9.7 cents for an Israeli number, with a 4.6 cent connection fee. I think that is for sending an SMS to an Israeli phone, but maybe there is a way for texts to come in bypassing your phone and go to Skype?