just be careful that you are getting the features you are looking for. The first post in this thread mentions the auto dimming feature. The OEM ridgeline mirror with the compass that comes with non navi trucks does not auto dim. It only has the compass.
I have installed several American manu OEM mirrors that I purchased from Ebay and local salvage yards. They have either been late model Donnelly or Gentex\Mito mirrors with digital compass, temp, and auto dimming. Last one I got was from a wrecked 2005 Yukon.
An average/good price on eBay for a used perfect cond mirror ~50$ plus shipping which can be a deal breaker, and they almost never come with the temp sensor. There are some ebayers out there that way overcharge for shipping. There are some other web sites that have wiring diagrams and such. You do have to be careful and get current model mirrors. There are lots of really old ones for sale on eBay. Also some have Onstar and other controls on them say for airbags and such which I assume you wouldnt want. Of course if you like to tinker, here is a option to add some other control for something to your mirror.
mirror ~50$ plus shipping
~15$ adapter plate from wedge mount to cam lock (from ebay)
~15$ temp sensor if you get a mirror with that feature. I just ran the temp lead and sensor down into the passenger foot compartment. Its sometimes interesting to see the temp difference between inside and out. It was just an experiment (and better than seeing the error code on the mirror display), but I was surprised to see that first thing in the morning when the inside truck and outside temps have stabilized, that the in dash and mirror reading are identical. Its also interesting to see that its 100 degrees inside when leave to go home in the evening. The only thing that I wasn't really happy about with the installation was how I tied into the existing truck wiring. Its all there, but I wasn't able to get the OEM Honda connector (without blowing my budget.. if you are not careful, you are better off just buying a brand new one with all the parts) I ended up just making a little cable with separate crimp on connectors which I individually plugged into the existing connector. Not the way it should be done, but I did insulate each well and made it secure. Electrically, its just as good, esthetically not as good and its all covered anyway. I got help from the HandA posted instructions for the optional mirror and XM install instructions that show how to remove the A panel trim