Hi George,

Thank you for contacting Mearto with your appraisal inquiry.

Blenko Glass is a renowned American art glass company, best known for its vibrant hand-blown glassware and mid-century modern designs.
Prior to 1982, most pieces were not marked and identification relied on design (using vintage catalogs), color, construction techniques and stylistic clues. From 1982-1999, the company used a sandblasted etched mark that read "BLENKO / Hand Made / USA"; from the 2000s to current day, pieces include either etched marks, foil stickers (that read "Blenko Handmade" or something similar) or paper hangtags for new or retail items.
Since you note yours had a sticker, that would date this to having been made in the last 25 years, so not technically vintage (for that designation, items need to be at least 50 years old, and 100 years old to be an 'antique.'

Variations in age can impact value, with older ones being slightly more desirable than newer examples; I suspect that would explain the discrepancy in the prices you've seen. Also, retail sellers will ask higher prices for theirs than private sellers, t though items sold on EBay are unregulated and nontransparent, with sellers being able to ask whatever price they like, even if it's higher than what an item might be worth.

When Blenko glass pineapple-form book ends made in the last 25 years come to auction, they usually sell for fair-market (akin to wholesale) values ranging from $40-60 for the pair.

Based on the photos and information provided, and subject to examination, this is:

A pair of modern Blenko hand-molded glass pineapple-form book ends
2000 or later
Each in the form of a halved pineapple, the flat sides used to support books. Unmarked.
Each 6 inches tall by 5 inches wide
CONDITION: These appear to be in good condition; value assumes no chips, breaks, repairs or losses.
PROVENANCE: Acquired at auction
$40-60*
*represents a fair-market value for auction purposes; retail or asking price may vary.

Please let us know if you have additional items to appraise, or questions/concerns, and thank you again for using Mearto.
~ Delia