The value of a complete set of 1989 Topps baseball cards can vary significantly depending on the condition and grading of the cards, as well as current market conditions. There are a number of factors that determine the potential worth.

The 1989 Topps set contains 792 total cards including regular issue cards, traded cards, rookie cards, stars and Hall of Famers. Some key rookies from the 1989 set that add value include Kenny Rogers, Gregg Olson, Bobby Thigpen, Jeff Bagwell, Kenny Lofton, and Chipper Jones. The condition of these high-value rookie cards is especially important.

To determine value, the first step would be to carefully examine each card and assess the condition or grade. The two main grading services used are Beckett Grading Services (BGS) and Professional Sports Authenticator (PSA). They grade cards on a scale of 1-10 based on factors like centering, edges, corners and surface. A complete set in PSA Gem Mint 10 or BGS Black Label condition could be worth well over $10,000. It would be extremely rare to find a set in that pristine of condition.

More realistically, if the set was in Near Mint to Excellent (PSA 7-9 or BGS 8-9) condition overall, it could fetch $3,000-$5,000 depending on individual card grades. In Very Good to Near Mint (PSA 5-7 or BGS 6-8) condition, expect $1,500-$3,000. In Good to Very Good (PSA 3-5 or BGS 4-6) condition the value would drop to $500-$1,500. Any cards graded below a PSA 3 or BGS 4 would significantly hurt the value.

Also affecting the potential sale price is the current supply and demand in the collecting marketplace. In recent years, as the growing popularity of card collecting has increased demand, values have generally appreciated. An oversupply of common cards on the secondary market could potentially decrease what a seller could get at auction or through private sale.

Another crucial consideration is the cards’ availability and completeness across the entire set. A missing traded card like Ken Griffey Jr. or Frank Viola could decrease the value considerably depending on what is absent. Conversely, having important short printed and error cards that are difficult to obtain could increase the worth.

Certain Hall of Famer and star players from the 1989 set carry premiums that lift the value. For example, the rookies of Greg Maddux, Tom Glavine, and Frank Thomas are must-have cards for collectors that routinely sell for more than their PSA grade alone would indicate. Conversely, common players see very little individual value.

While there are definitely variables, as a general guide a complete 792 card 1989 Topps baseball set in Near Mint to Excellent condition could reasonably sell for $3,000-$5,000. Very Good to Near Mint condition around $1,500-$3,000. And Good to Very Good closer to $500-$1,500. The condition of key rookies like Bagwell, Jones, and individual star and HOF player cards would be deciding factors within those rough price ranges. Proper grading only enhances the potential return.