I replaced both interior sliding door mechanisms, one outside handle and one rear hatch handle. They're real easy to do. If you can change your oil, you can do this. They each take about 30 minutes at the most to do. Don't be intimidated.
I think the outside handle was $90.00 from Toyota, but it was painted to match the factory color. The inside push button mechanisms were about $40.00 each and the rear handle was about $60.00.
All you do is remove the interior door panel with a putty knife. Then pull away the plastic waterproofing membrane and unbolt the old, replace with the new.