I am the queen of free cheap entertainment..
The library has lots of freee events for kids.. check troy.. also look at the other libraries in your area... royal oak sterling heights.. etc... some libraries are a pain and require that you be a resident to come to a program or sign up ahead of time.. others are open to anyone ..
Sterling heights is a great library.. they have no registration for most programs so just come whenever.. the room is large and the librarians are great.
Oakland shools runs FREe playgroups throught the county. It is on the oakland.k12.mi.us website.. look under early childhood and it is a couple of pages down..
Join a moms club.. great way to meet other moms and kids..
Centerline public schools has a fabulaous playgroup.. meets wednesday mornings.. $5 per week.. it runs throughout the school year and was a lifesaver for me..
I try to find classes that are under $10 per session.. because I have 2 kids and entertaining them can eat up my budget.