UP for sticky.
Additional tips on shutter actuation check, maybe you can ask the seller for a sample image that is unedited taken recently by the camera, and examine it's EXIF data.
There are several ways to do this, if the seller has a flickr account, you can ask if he can upload an unedited image and then from there click on more properties, since the flickr uploader (as of this writing) will not strip down the EXIF data. Actual Shutter Count can be found on the image's EXIF.
Or you can ask the seller to email you the sample image and then use a free utility that reads EXIF data. One such tool is the exiftool by Phil Harvey