Back to what the OP was saying. Helmi, I believe there are three reasonable things likely taking place here.
1) The S2 purchaser decided sooner than later to upgrade to the core line as has been previously stated above.
2) The purchaser over extended themselves with the purchase and had to sell. A very common happening with guitars at this price point, regardless of brand.
3) The purchaser expected the moon and the stars and private stock treatment for the price point and was disappointed. No brand is ever going to make everyone happy, it just cant be done.
Now I will add this. The price point of an S2 is a very popular one. Factoring in #3 above and the likelyhood of buying online, you have an issue of $$$ not the guitar. Buying online is about the money saved, never the guitar. End of story, regardless of the details! I hear of more guitars bought online being returned than those purchased for ever so slightly more from mom and pop shops. Relationships with the store owner, are important. Never more important, to me anyway, when buying a PRS from them. Mom and Pop shops complete the experience and are worth the tidbit more in cost. That said, buying a PRS is an experience in and of itself. Buying online and thinking about the money is about self! Not the instrument or what was put into it. It was about the price. Those type of online purchases miss out on the PRS experience. Alot of selves' cant be made happy because thy are chasing the dollar and have to sell a great instrument in their pursusit of getting something for nothing and being cheap and pursuing being happy with getting something for nothing. I dont know if they will ever value the PRS experience because it was not cheap. The S2 guitar is a steal at the price point for which it is offered. Unfortunately it appeals to alot of cheapskates who have unrealistic private stock expectations from a working mans (read musician) guitar. They have to sell because PRS did not go broke enough to try and please them. Dont buy online. Feel the experience and play PRS in a store who has invested their money and confidence in a product that was made with the investment of sacrificial dedication that will always deliver. That experience is not felt on line, it is only free shipping! Hopefully though, #1 above is being successful. I bet it is!
PS, I guess I just went on a rant. Sorry! If this makes me a PRS Snob, I guess I am guilty.