1952 Topps psa pricing vs. actual value

[journeyto407]

For the last month or so, I've been tracking 1952 topps on eBay and trying to get at least an idea of what PSA says something's worth and actually how much it's worth.

I used PSA 5 as my base (which is what I'm collecting) and this is what PSA says they are "worth" - this is just for commons, no big names, HOF, RC, etc.

Commons 1 - 80 - $40
Commons 81 - 250 - $28
Commons 251-310 - $30
Commons 311-407 - $140

What I've found that they are actually selling for is more along the lines of (again PSA 5):

Commons 1 - 80 - $25-30
Commons 81 - 250 - $15-20
Commons 251-310 - $20-25
Commons 311-407 - $160

So, from my unscientific look through, it seems you can basically take off 1/4 to 1/3 of the price for cards 1-250, about 1/4 for cards 251-310, and anything over 311 is in high demand.

Just interested to see if any other collectors have seen these trends as well with 52 Topps? I'm trying to get a general feel for pricing so I a) don't get burned and b) can look for good deals online/at shows.