Keyless Remote Entry Problem

2002 Toyota Highlander
It is becoming increasingly harder to gain entry
on the driver side door. It started several months ago - the keyless remote would not lock or unlock the driver side door (it works for the other doors). I used the key to gain entry - now the key is not always working. I'm afraid that I soon will be crawling over the center console to get to the driver's seat! I am reluctant to take it to the Toyota dealer due to the expense I will probably incur. Thanks for any help you can provide!