A 6 year old machine with no prior service history will probably need a quite a few parts. At the bare minimum, it's going to need a new pump and OPV and the solenoid seals checked for damage. Either of these could be the cause of your low pressure issues.
Other repairs will be steam boiler o-ring replacement, steam level probes checked for scale build up and replaced if required. Depending on the level of scale found will indicate if a descale is required.
There are several other common problems that affect these machines after several years but sometimes you get lucky and you get a good machine. I had a 2012 machine in today that had the original solenoid and steam tap which were in perfect working condition. They are also common parts that can fail.
Last week I had an early 2011 model that I fixed once in 2014 (for warranty issues on the very early models) then again now. This time it was all the common repair items. The machine had close to 12,000 shots on it and the customer has only just had to spend a bit of money on repairs. Pretty good for an appliance I think.