Workshop costs VW, Renault, Opel

Hello together, I have found a car in the meantime a Renault Laguna Grandtour 1.5 dci DPF 110PS. This car tells us so far. As an alternative would be to call Skoda Octavia/ Golf (Kombis) 1.6TDI and the Opel Astra Tourer 1.4 CDI. However, I worry if it is a Renault to be faced with high workshop costs. The Laguna is also not exactly the “world car”! But with 40,000km and good equipment from the year 12/11 is just 10.800€ not much if you have it with a only the Opel would be better equipped but also worse equipped. Can someone give experience and or recommendations at which the least workshop costs would occur. I admit that I can get an engine damage with each of these cars 🙁