The lock button on my car key fob hasn’t been working for ~ 6 months. I was looking at buying a new key fob for between $9 to $35, but something told me to take it apart.
Some isopropyl alcohol, a used toothbrush, and 5 minutes later I discovered some kind of sticky blue goop had infiltrated my key fob. After a quick brush down and slight emersion of the lock button, my key fob is now working again.
My girlfriend’s stopped working and fell apart into pieces sometime last year. So, I talked her into replacing it. I called a locksmith and was quoted less than $100 on it, probably like $60-$80. She went with the dealership for like $400.