Mercedes-Benz SLK Buyer's Guide
Eleven tracked SLK sales at a £2,400 median make this the cheapest route into Mercedes roadster ownership by a wide margin, and the £670-to-£30,250 spread explains itself: ordinary R170s at consumable money, AMG versions climbing into collector attention.
Know your generations
R170 (1996–2004). Seven sales, £670 to £16,350, median just £1,370. The generation that popularised the folding steel roof; the £16,350 top result is SLK32 AMG territory, the supercharged rarity worth seeking out. Ordinary 200s and 230s are now priced below their own roof repairs.
R171 (2004–11). Two sales at £2,289 and £2,400. Better built than its reputation, with the 350's V6 the pick; the SLK55 AMG, a naturally aspirated V8 in a small roadster, is the future classic of the family.
R172 (2011–20). Two sales at £6,500 and £30,250, the top result being AMG money. Still on the depreciation slope; buy to use.
What to pay
£1,000 to £2,500 buys running R170s and R171s around our medians; treat the purchase as prepaying the first repair. £4,000 to £8,000 buys the best standard cars. AMG versions run £15,000 to £30,000 in our results and justify it: they are the only SLKs the collector market has so far admitted.
What goes wrong
The vario-roof is the model: hydraulic rams, seals and sensors fail with age, and a roof that hesitates at the viewing is a four-figure quote in waiting. R170s add the era's rust (wings, arches, boot floors) and, on early cars, the wiring-adjacent gremlins of late-nineties Mercedes. Engines are durable throughout, the supercharged fours needing only honest servicing. The rule from our SL guide applies at a smaller scale: bills are Mercedes-sized even when the car cost £1,370.
Our view
As a keeper, only the AMG cars make the argument, and the SLK32 at our £16,350 result looks better value than its R172 successor at nearly twice that. As transport with a party trick, a £2,000 R170 230K with a working roof and history is tremendous fun per pound; just never pay for potential, because the ordinary cars have none left to price in.
