Infants can be harder for agencies to place due to the expense of care for an infant. If you choose to foster infants, you need to think about if you will need child care. It is possible in some cases to be reimbursed for day care expenses (it is a limited amount and you may have to go on a wait list, so do not count on it for sure) but for the large part you will be responsible for the expense up front. You can get formula though WIC, see another posting here about this.
The cost of bedding is not important but how it washes is the most important thing. Remember there many be times that you are washing the bedding on a daily basis. Sheet protectors are nice to have when dealing with small children and bedwetting, since you just have to change the protector instead of full bedding change in the middle of the night. So, having a few of these on hand could be very helpful to you.
Remember, there will be great wear and tear on things used for foster care and at times items can be destroyed. So, you might want to keep this in mind when you start purchasing items for foster care.
With teenagers your cost and need for additional hygiene products will be necessary (deodorant, feminine products, hair care products, etc.). There will also be activities that they will need to be involved in at school and for extra curricular activities to help develop social skills, to help keep them out of trouble which will also have expenses. Since they are foster children sometimes the fees can be waved or reduced, so be sure to ask without involving your foster child (this can just add to their low self esteem).
“Don’t go through life, grow through life.”