As of 2014, a Daisy Model 188 BB airgun in good to excellent condition sells for approximately $35 at an online auction. A complete set that includes the gun in its original box with the original manual and bullets can sell for as much as $65.
The website for the Blue Book of Gun Values also provides paying members with yearly up-to-date price information on a wide variety of gun makes and models as of 2014.
Daisy Model 188s BB airguns were manufactured from 1979 to 1989 using heavy diecast metal. They were discontinued due to their highly similar appearance to real guns.