my disclosure-the first degree I received in college was in early childhood education which included a great deal of instruction on the legal issues of operating childcare in both centers and private homes (which the laws have greatly increased regarding in the many years since) that said-
if someone is accepting less than $3.15 per hour to care for an infant ($100 per week divided by 40 hours per week or $25 hours per day divided by 8 hours per day)
on the basis of not minding the "inconvenience of having them around" it is not necessarily someone who is providing what many parents would consider as acceptable childcare (regarding providing the appropriate safeguards in the event of an accident or emergency).
i'm not knocking the childcare these people are providing, but honestly-I don't know anyone that would begin to consider hiring a babysitter for an evening out and paying anywhere as little as this amount.
as to considering going into business based on the amounts quoted in this thread-take into consideration the following:
if the number of children you potentially watch require licensing or not-if (god forbid) an accident or illness occurs that causes a parent to file (or their health insurance on their behalf) a claim on your homeowner or renter insurance about-absent having notified, contracted and paid that higher premium that childcare requires-you as provider are looking at substantial personal financial liability as well as cancellation that can result in unaffordable future coverage that is in violation of mortgage terms,
if you pickup or transport children for whom you receive financial compensation and are involved in an auto accident (even not at your fault), and your auto carrier finds you are using the auto that you've not notified, amended and paid them to use for "business purposes" was involved, count on your insurance being cancelled which will result in much higher premiums even if you discontinue child care, and yourself being liable for all expenses.
this may sound drastic, but it's the drastic situations that cause major issues.
even the minor issues can cause drastic issues. your well meaning, low paid neighbor is watching your child and 'just needs to run to the store for a second' so they take your kid along but because your kid doesn't normaly ride in their car they don't have their booster seat. there's a minor fender bender and your kid gets minor injuries. your health insurance says the couple of thousand in e/r fees are on the neighbor's car insurance, their car insurance says b/c no business insurance they aren't covering. you are left dealing with a former 'good neighbor friend' whose arguing that what you're asking for in med bills is more than what you agreed to pay her for 3 months of childcare


it's a very bad situation all around.
honestly, with childcare it's like everything else-you get what you pay for.