When you 'get your tracking done' it is generally just the
directional alignment of the front wheels that is looked at, and typically very basic equipment is used, if any. Companies usually charge �5 - �10 for this, so it might appear to be a bit of a bargain but I've found it's usually a false economy. I now always go for digital 4-wheel alignment, which normally costs anything from �20-�40 (�65 sounds a bit steep - who quoted you that? A VW dealer?) from a specialist tyre/exhaust place. The 4-wheel alignment normally takes about 30 mins depending of the level of adjustment required, and involves the clamping of measuring heads on all four wheels and using infra-red they then measure axle misalignment and the computer screen shows them what degrees of adjustment are required. The adjustments themselves don't take long, and they should give you a 'before and after' printout as a record of the work done. The result should be even tyre wear and better handling, but drive carefully over speed bumps and don't mount the pavement as this will definitely throw it out again. I generally get it done every six months as required. As to whether it's necessary, how much do you pay for your tyres? If you have Pirellis at �170 a pop or more, I would say definitely, but if remoulds at �80 a set are your poison you might want to have a rethink....
BTW lots of places will check for FREE to see if adjustment is required, and only charge if you get it done - always worth asking!