How much you spend per month depends on you-if you walk a lot vs. taking the bus, go shopping, buy a lot of food, go out to eat, etc.
Personally, I spent less than $100 per month, but i had friends who spent double the amount. But to be fair, I walked most places, and the money was mine that I earned, and it wasn’t unlimited, so I was a lot more careful… depends really on a few things: you and your spending habits, your financial situation, and if you’re willing to give up american products and buy cheaper israeli things, which for the record, are NOT inferior! Just not what you’re used to.
Laundry-depending if you have to pay for the washing machine, how often you do laundry, if you wash stuff buy hand… Several friends and I bought a basin (about 3 shek each) and a thing of hand washing detergent, and that saved quite a bit.
When you budget, keep in mind gifts for your shabbos hosts, transportation for shabbos, and all those little things that add up
There will be months you spend more (ie adar, and the rainy months when you don’t want to walk) and months that you spend less.
What i found worked very well was to set out half the money i brought, say i’m only spending that, and divide it up into even amounts for the months. this way, in a month i spent less, ihad money for a month i spent more, and i had money to fall back on if needed, so that i came back with money left…