The first step is to determine the age and condition of the cards. Baseball cards from the 1950s, 60s, and early 70s are usually the most valuable as those early production runs had lower print runs. The further back you go, the rarer the cards become which drives up value. That said, even 1980s and 90s rookie cards for star players can retain value.

Once you know the approximate era, you’ll want to assess condition. Base set common cards from the 50s/60s in worn condition may only be worth a dollar or less. But a rookie card of a Hall of Famer in top-rated mint condition could be worth thousands or even tens of thousands. Condition is key when determining value, so you’ll need to examine each card closely.

Look at the corners – are they still sharp or are they bumped and rounded? Inspect the edges for wrinkling or damage. Check the surface for scratches, fading, or staining. The lower the grade on a 10-point scale, the less valuable. Near mint (8-9 grade) cards can still hold value but anything worn (6 or lower) will likely only appeal to collectors looking for play copies.

Knowing the player featured is also important. Rookie cards, especially of star players who went on to have great careers, are usually the most valuable. But even stars have odd-ball rare variations that could increase a card’s value exponentially. And sometimes unheralded or failed prospects have error cards that are then chase pieces for collectors. It pays to do research on each player.

Once you have an idea of approximate era, condition, and featured player, you can begin researching prices. The best way is to search for recently sold listings of comparable cards on platforms like eBay. Be sure to filter for sold/completed auctions only as active listings often overstate true market value. Target recent sales from the past 6 months to a year for the most accurate ballpark of what a card in similar condition might actually sell for.

Beyond eBay, websites like PSA Card, Beckett, COMC, and Sportlots are also good resources for baseline pricing. Cards that are professionally graded bring premiums compared to raw, ungraded copies. So find comps taking the grading into account. Also be aware that “collection” lots (groupings of cards) usually sell at discounts versus singles.

After doing your homework, you may find cards that on initial inspection look like duds actually have key details that make them potentially valuable – whether it’s an error, variation, rookie card of future star, or other scarce parallel. Always study the minutiae and double check player/production details before writing anything off as worthless.

The values of even the most common cards can fluctuate based on player performance updates or increased broader collecting interest. So while a baseball card collection sorting may not initially yield instant fortunes, with research some hidden gems could be worth meaningful money – especially in top-notch preserved condition. Taking the time to properly evaluate each one using available resources can reveal surprises.

With patience and a diligent process of assessing factors like era, condition, player, and comp prices – you’ll be well equipped to tell whether those old baseball cards collecting dust may have some latent financial value after all. Even if strict “money” value isn’t found, the nostalgia many feel alone can make revisiting a childhood collection worthwhile.