Amazon offers the Dyson Tangle-Free Turbine Tool Vacuum Attachment, model no. 925067-06, for $38 with free shipping. (Walmart charges a few cents more.) That's tied with last week's mention as the lowest total price we could find by $12. It's compatible with all Dyson upright and canister vacuums from DC23 onward (except DC24 and cordless models). Features include elliptical counter-rotating heads with integrated brushes and an articulating base plate.
Walmart offers the Stanley 16-Piece Passthru Set, model no. STMT74900, for $19.97. Opt for in-store pickup to avoid the $5.99 shipping charge. That's $10 off and the lowest price we could find, although it was $5 less in September. It features chrome vanadium steel.