If you’re looking to buy a euro 6 set aside £2.5k for the DPF filter change. We bought a scania g250 and after two weeks and 470k on the clock the DPF had to be changed £2.6k incl vat.
Depends on where/how you will use your lorry.
If its general haulage I would steer clear of the Daf and Merc.
Both are thirsty. Our Scania is about 1-2l better per 100km.
The ZF Astronic on the daf is rubbish (we had two 12 plates with 400k on the clock and both packed in £3.5 each to repair)
The auto gearbox on the merc is alright as long as it goes. We were unfortunate and ended up selling our actros after we had accumulated bills of over £10k in repairs (both from dealers and local workshopsworkshop + recovery)
Scania with a three pedal opticruise or a volvo with an Ishift gearbox would be my recommendation. But again it all depends from the work you will do.