To save money, they should just get a cellphone. Plans with Golan and Hot offer unlimited calling AND texting to the USA (along with about 40 other countries,) and unlimited domestic calling/texting, and unlimited internet with speed throttled after 3 GB for NIS 99/month including tax. Internet will be more expensive than that after the first few months.
If you really want the internet, there are a couple of options. One is Netvision. Another is HOT. Or Bezeq.
Prices will be around NIS 170 for 12 MBS.