First - call or email your priest and tell him you have no idea what to expect and ask him what you need to have ready for him. If he's no help, call Matushka or a deacon or someone you know from the parish.
You should have holy water that the priest blessed on Theophany. This is what he will use to bless your house. A bowl for it to go in. And a list of names of those who live in the house so he can pray for your family by name. A candle and matches. That's really all you need for the blessing. My priest also likes to bless all the beds as well as rooms. (including bathrooms and laundry).
I usually give my priest about $25-30. But, it might depend on where you live too. I would think that if it's a mission parish and the priest has full-time job outside of the church, the parish is probably not able to pay him much. Giving him something with that in mind might help you a bit. I look at it as a honorarium rather than gratuity. Ask your priest if he has other houses to go to after yours.
My priest will take a gift of money but turns it into the parish treasurer for the support of the church, this is not the way I have usually seen it done but he always tells the parish that his salary from the parish is all he expects and that any oter gift is to the Church not him as the pastor. He does not allow charges for sacraments or any other sacramentals.
While your Antiochian church or Greek Orthdox church might pay the priest enough to be able to afford luxury items such as up-sizing a value meal Slavic churches don't pay their priests enough for even this small luxury.
I know a total convert parish in the south that pays the priest 36k and he has a gaggle of kids. No one thinks they should give him twenty or thirty bucks if he drives an hour to bless the house.
They say his total financial needs are covered by the 36k a year and it's on him to pay for gas, etc.. to do his works.
I am not going to tell you how much most Slavic (Serb, Russians [including OCA], Carpatho-russians, Ukrainians) get paid. But please give the priest some money.