We have all manner of skillets...restaurant types, department store kinds, etc. Some came with lids. Others, most, didn't. I like having a lid.
So...over the years I have found lids for all of them at such places as Goodwill, Salvation Army, thrift stores, consignment stores, etc.
The most I've paid for these lids is one US dollar. Many of them are tempered glass, which I love and allow me to see what I'm cooking.
Check these sources in your area. You might be pleasantly surprised.
"As a girl I had zero interest in the stove." - Julia Child
This is real inspiration. Look what Julia became!