RC Card Focus: Andrew Bynum - SPx vs SP Authentic

For the past month or so, I've been watching actual sales for two key RC cards of Andrew Bynum. These cards are their SPx Auto/Jsy RC & SP Authentic Auto RC. Both cards are mid-high value range and I feel a decent bang for the buck.

Andrew Bynum SPx Auto/Jsy RC #'d 1499 - This card's BV in Dec was $40, then jumped to $50 in Jan. Dec sales on ebay (I tracked 14 sales from 12/2 to 12/23) averaged $36.21, just a 90.5% of BV (vs Dec BV of $40). The high was $44, and the low was $27.

Andrew Bynum SP Authentic Auto RC #'d 1299 - This card's BV in Dec was $30, then jumped to $40 in Jan. Dec Sales on ebay (I tracked 14 sales from 11/24 to 12/27) averaged $34.06, 113.5% of BV (vs Dec BV of $30). The high was $56, and the low as $22.79.

Even though the SPx had the jersey swatch & $10 higher BV, buyers didn't necessarily value it much higher than the SPA. The difference in average selling price, for roughly the same time period, was only $2.15. My opinion to explain this is the autograph version used (refer back to my previous discussion on 11/27 - Player Focus: Andrew Bynum Auto Variations). The SPx uses the VERY common "AB #17", which I think will become even more common as the years go by when this becomes Bynum's normal sig. The SPA on the otherhand uses the less common "Andrew Bynum" sig. As I mentioned before, players' sigs usually get shorter as the years go by (Ex. Kobe Bryant --> Kobe 8 --> Kobe). The impact of the difference in serial # (200) is pretty much nil.