Welcome to the forum, edjs.
The best way I can think of to answer your question about a common PSA 8 '33 Goudey is to refer to PSA's price guide:
http://www.psacard.com/SMRPriceGuide...?SMRSetID=1092
PSA breaks down the commons by card number in two ways:
Group 1: Cards # 1-40, 45-52
Group 2: Cards # 41-44, 53-240
Commons in the first group at PSA 8 are valued at $1,175.
Commons in the second group at PSA 8 are valued at $400.
These values reflect PSA's last update as of January 1, 2014
Please keep in mind that this is just a starting point, and the market could be noticeably higher or lower. To get a more accurate indication on where your particular card has been selling in a PSA 8, you would check cardtarget.com, or do a look up on VCP (vintagecardprices). VCP is a pay service, and card target is free. You can do a 24 hour membership to VCP for $3.99 (or maybe somebody here with a VCP membership could help you out).
https://www.vintagecardprices.com/register.php
If you give us the player name/card #, we can help you from there. 
If you have any questions, please feel free to ask.
You'll find a lot of information, and some really great people here. If you want to learn about pre-war and vintage collecting, this is the place to be.
Have fun!
Bill
__________________
Building these sets: T206, 1953 Bowman Color, 1975 Topps.
Great transactions with: piedmont150, Cardboard Junkie, z28jd, t206blogcom, tinkertoeverstochance, trobba, Texxxx, marcdelpercio, t206hound, zachs, tolstoi, IronHorse 2130, AndyG09, BBT206, jtschantz, lug-nut, leaflover, Abravefan11, mpemulis, btcarfagno, BlueSky, and Frankbmd.
|