Thank you for submitting your items for appraisal. This appears to be a pair of late 20th century tubular steel cantilever armchairs inspired by Marcel Breuer, Mart Stam or Ludwig Mies van der Rohe, but manufactured much later than the mid-century era. This appears to be a product manufactured by an asian manufacturer and not Thonet for example. The apparent wear on the backrest could be an indication for this assumption.
The estimate is based on similar anonymous design chairs offered or sold at auction.
"Asking" prices in the trade are often much higher.