Dan Marino/Troy Aikman - C: 1992 Upper Deck - 8.5x11 Commemorative card

OTHER WAYS TO SELL YOUR CARDS
•eBay Buy-it-Now •card store •swap meet •Craigslist •garage/yard sale
or •DONATE to a charity for tax write-off
Not selling but perhaps easiest with possible $$$ return.
ASSUMPTIONS:
#1) You are one of the RARE tax payers left in America
#2) You have mostly late 80's & 90's "junk"
Consider donating the "junk" and keep better stuff to sell later. Tax deduction was based on LESSER of "what-it-cost" & "What-it's-Worth". For "What-it's-Worth", I use Beckett which can be higher than what you paid. Check with your tax guy.

Cut/Paste TurboTax discussion link below:
https://ttlc.intuit.com/questions/3372284-are-trading-card-donations-deductible-if-so-how-much Possible Charities for Donations
•Goodwill   •Salvation Army   •Cerebal Palsy   •Children's Hospitals   •Cubs scout troops
...or an online charity
  •Cards 2 Kids   •Commons4Kids.org   •CollectiblesWithCauses.org
Verify all "charities " before donating.

Generally, team signed baseballs from early 1900's had 10 to 15 signatures, the 1940's that jumped to 18 to 25. Joyce Sports Research Collection (Notre Dame) says "signatures must include only members of a specific team from a specific year, and there must be some approximation of completeness."

Not concrete but to me a "team ball" MUST have ALL the team's STARS (unless a rookie or in season trade) and in today's market at least 20, preferably more, and the manager.

Determining Age of Team Signed Balls
"Official" league balls have stamped signatures of current league presidents on the "sweet spot". Starting 1934/1935 balls were produced by Spalding (NL) and Reach (AL). Rawlings took over in 1977/78. Have a possible team roster at hand, ESPN & baseball-reference.com have great sites), decipher a few signatures then solve the puzzle.

Team Signed Baseballs Values
Pricing team signed baseballs is difficult due to subjectivity and factors involved suce as: Signatures placement, quality, strength, number of autographs, stars, age, team significance, and eye appeal considering fading, whiteness, scuffs, shellacking, staining, overall wear...

Team autographed baseballs on official league balls get higher values. They are "official", made better, preserve better and even help in dating especially with balls signed at "Reunion" baseball card shows which brought together great teams of the past.

Facsimile Autographed Balls
1960's/1970's machine-printed "autographed" team baseballs were sold at stadium gift shops for around $1.95. Easy to identify as all signatures were uniform in ink, color, size and look. "Facsimile" signatures are also often found on baseball cards.