1981 topps baseball cards including fernando valenzuela rookie cards are listed on this page with current ebay auctions
This set is right on the threshold of being considered a bonafide vintage baseball card set. I personally recommend that collectors own a set of the regular series and also the traded set. It is the first year that Topps issued a traded set of 132 cards. There are rookie cards of Harold Baines, Tim Raines and Fernando Valenzuela (there is an additional rookie card of him in the Traded set as well). These cards can run about $60-$100 for an unopened wax box and a little bit less than that for a complete master set and a bit less for just a 792 card set.
There are many hall of famers in the set highlighted by Rickey Henderson's second year card, George Brett, Pete Rose (not a hall of famer), Robin Yount, Mike Schmidt and many more. There are multiple cards of the players because there are highlight cards as well. These book well in the Beckett price guides, if you have a copy to look at it is worth looking up. There are many cards worth more than $1 in the set and this set has great long-term potential for price increase in my opnion because it was still not yet to the point of overproduction according to many people.
A great place to buy the cards is at your local dealer or card show because you can see the condition in person. I find, however, that buying them on ebay from a reputable seller that promises the condition of the cards is better because you can get a better price and in many cases you are buying from a fellow collector that is just selling part of their collection. Those are the best deals is when someone wants to get rid of their cards and does not list cards often many times.
I highly recommend this set because it is undervalued and a great borderline vintage set.