Comment apart from moving ... (Score 1) 474
Double windows, like in BMW luxury cars, 7-series has been doing a long time. Thick windows too, custom made. Not that expensive really.
That is if you must have natural light coming in still, which you obviously want.
Active noise cancellation is not that expensive anymore, i recall seeing headphones for 100€ or so with active noise cancellation!
You could hack from that set a cheap active noise cancellation system!
A little bit of experimenting is required with the location of the receiver microphone to get the timing right, and the distance of the reflector if reflector is required.
As for other surfaces:
Look at car acoustics, there is many types of noise insulations! Some are cheap, some a little bit less cheap. Common in everything: Comes in easy to apply format, "mattress" or "paint".
The "paint" type is usually very massive and to be applied thick, often just bitumen which is very cheap. Will not "dry" ever completely necessary. Thickest form needs to be applied with heat.
The "mattress" types are usually for specific types of noise, the bitumen type usually is best used to stop vibrations etc. in cars, and functions for all types of noise. The mattress types are usually lightweight and thus usually effective only for certain bands.
Often the mattress types also include heat shielding & insulation.
The cost per m2 ranges from couple euros to 30 euros with these, but i'm sure you can get them in big quantities far cheaper than that.
Downside is that these are only suitable for inner structures, so if you live in brick / concrete building you'd need to build separate inner walls too, thus most likely not suitable to your application.
Active noise cancellation might be the best bet here.