Our basic philosophy with map data is that if it is free to us, it will be free to the customer. I can't say for sure that this will be true with everything forever, but with all data we see today, that is true. That doesn't mean we can implement every free database in the world though, as it does take us significant work to support a database so the demand must be there.
For instance, in the USA, approach plates are free, but there is no free source of georeferenced plates that we know of, so simple plates will probably be free but there is no way georeferenced ones will be. The FAA provides some airport diagrams which are free, but there are larger sets of them out there that cost.
Airport, airspace, obstacles, waypoints, VOR's, remarks, frequencies, and a lot more are already in our databases today and will never be pay for. If by "IFR routes" you mean airways, then those will also be free of charge when we implement them.