Absorption Centers used to be the choice for many Olim. Today, there are less of them and it is difficult to get into one and the terms for staying in them have changed. If you have almost no Hebrew, have no where to go, and very limited funds, consider the option of an Absorption Center, keep in mind that you must reserve a space at least 6 months in advance. The price goes down considerably once the child enters kindergarten. Transportation, entertainment, and the like are all extra.
High school is another matter.
Housing Rental prices depend on the area you choose. Remember, you get a rental subsidy for five years. The amount depends on your family size. The biggest chunk of your Aliyah expense will be purchasing an apartment. Each neighborhood is different even each apartment is different.