It is very low kays to have to machine the discs. The squeal you're hearing is not normal, so I would take the car to a brake specialist, who I'm sure would be able to help you fix the problem. Maybe the discs don't need replacing. If they do you could use aftermarket rotors, which should be cheaper than the factory ones.

Normally I would expect your speedo to be around five percent fast, in other words it's reading five percent higher than the actual speed you're doing. Under the law it could be as much as 10 percent fast, but on average most cars appear to be closer to five percent. You could have the speedo checked by an instrument maker, but I would suggest you first check it against an overhead speed indicator on a nearby highway. While they are not necessarily 100 percent correct, they are a good guide. You could also check it against a GPS unit, which would give you a good indication of a problem.