2007 Toyota Sienna passenger sliding door problems

On my 2007 Toyota Sienna, the right side rear passenger sliding door has started to give me problems by not wanting to open when I hit the over head door switch, or press the door open button on the key fob or the switch at the side door pillar but will work when I pull the outside door handle or the inside door handle. I was going to take the van in to a toyota dealer but my wife made me feel guilty when she said that I'm a mechanic and I should be able to fix it myself so I got some help online by doing research and sure enough, there are many complaints about these doors on the web. I went to this website townhall-talk. and found a man with a similar problem who was able to fix his van. Based upon the symptoms he was having and it as similar to mine, I was able to do a simple test that he suggested which in turn nailed the problem down to the door lock actuator on the right rear door. Toyota wants about $1200.00 to fix it. I looked up the part online and found the dealer price at around $450.00 I found it at another website for about $125.00 Well, that's a lot cheaper than paying $1200.00 to have someone fix it especially when I'm a mechanic. Now I just need to come up with the cash to buy the part.