Correct me if im wrong guys, but im almost certain there is no 1a.
Card #1b is the trade card ($20bv), and card #1 is the RC thats $40bv.
Both cards look the same, black background, 3-frame picture of Shaq dunkin.
The only difference being card# 1b has "Trade Card" on the front of the card, and card #1 has "#1 NBA Draft Pick" written on the front.
The other obvious difference is that one's number "1b", and the other ones numbered "1"
Theres also a European version, which is exactly the same design, but its got a white border on the front of the card.
1992-93 Upper Deck 1 Shaquille O'Neal SP RC ! $15.00 $40.00
1992-93 Upper Deck 1B Shaquille O'Neal TRADE $8.00 $20.00