Last year we made these
I stumbled upon this template. We all (me and the kids) cut out the templates. I printed "Happy Valentines Day From So and So" on address labels stuck it on the inside with a hershey kiss in and voila, valentines.
This year the kids wanted to do something different again.
We decided on seed packet valentines
Mailing labels, $1.44 (originally $4.44 had a $3 off coupon)
400 sweet pea seeds from Ebay, $7.95
Coin envelopes, I have no idea. We have had these forever.
Total Cost $8.39
Not bad for three kids and doing something a little different for Valentine's Day.