Picking the right foreign associate is absolutely critical to foreign patent prosecution. You want foreign associates that can provide insight into the patent laws and strategies of its their respective countries, not just a mill that churns out paperwork.
You also want to choose associates that bill according to the amount of time actually spent on your project. Almost all patent firms outside the U. S. do the just the opposite, charging according to a fixed fee schedule. That sounds appropriate, but is usually a recipe for overcharging. By charging fixed fees for simple tasks, it is very common to an associate to effectively bill hundreds of dollars an hour for simply putting an envelope in the mail, or handling a quick phone call.