The very best examples of these cars can be often be found on dealers' forecourts for around £5000, while projects can often be had for around the £500 mark. So you can see there's quite a big difference in price when it comes to condition. There's no doubt a car is easier to sell if it's up, running and roadworthy (i.e. has an MoT). But it's a catch 22 situation, because you won't really have an idea of what it needs to get running again until you try. You might find that the car will come to life with a fresh tank of petrol and a new battery - in which case you'll just need to give the car a full service with new coolant and fluids. On the other hand, you may discover that it requires significantly more work than you realised to get it through the MoT. Here's what I'd suggest, find a local garage that you want to work with (use our Good Garage Guide: good-garage-guide.honestjohn.co.uk to make a shortlist) and speak to them about doing an inspection. Not all garages offer this service, but if you can find a good Mercedes-Benz specialist they should be able to give you a list of all the cars faults - and an idea of which ones need fixing to make it roadworthy. Make sure you ask for this to be priced up with labour, parts and VAT. Remember, this is only a guide - fixing cars is always an adventure. Fixing one fault leads to another and jobs always take longer than expected and often require extra parts. But at least it'll give you an idea of how much you'll need to invest to upgrade your car from a £500 non-running project to something you can sell for £1500-£2000. You don't have to fix all the faults - but any potential buyer will appreciate an honest appraisal of any work that needs to be done. Remember these prices are only a guide - you'll need to have a look at some current models for sale to get an idea of where your car fits into the market and price it accordingly.