My first Astromart Classifieds experience

I have never bought or sold anything used on Astromart before. But I had to give it a shot. I have 14mm and 21mm Pentax XL's on the way to add to the two I have. I pray my calculations with the binoviewer are correct. So far it's been very smooth. I can see how the rating system is so important. Everybody seem's so concerned with that , and it seem's like it could make or break your buying and selling success. I'm probably going to try the selling part soon with my Pentax XL Zoom and my Takahashi (sorry babe). Is paypal the prefered way of doing it. Is that the smoothest way?.I know some of you are old hat's at this, so any comments would be great. I'll delete this if it is off topic... Thanks guy's.