Samsung Galaxy S21 SM G991U 128GB — Used market price, United States
A used Samsung Galaxy S21 SM G991U 128GB typically sells for $150 in United States as of 2026-08-11, based on 96 observed sales. Half of all sales fall between $129 and $193.
What a flipper should pay
Buying below $129 leaves room for fees, postage and a returns allowance when you resell near $150. At or above the typical price there is no flip in it.
Underpriced listings right now
Live listings priced below the typical used price. FlipGap estimates the gap to market; verify condition and seller before you buy.
How this price is computed
The band comes from live eBay comparables and FlipGap's own cross-marketplace listing corpus, trimmed to the interquartile range so bundles, parts-only and sealed-new listings do not distort it. "Typical" is the median of that trimmed set. Bands refresh whenever the product is priced again and pages are only published when the sample is large and consistent enough.