I don't even know if this word '"aerograph'" exists in English.. Well i mean the basic thing that i use with an air compressor and which is pictured below. I always rant over the fact you can usually do pretty nice things with no money when it comes to model making, here's a proof. Look at this horror, it's the most basic Aztec you can find which i bought more than 10 years ago. It's awful, works when it wants to, but i still can produce some fairly okay things with it :) My compressor I have for the last 20 years, it's a basic compressor for car tires, i got it cheap because it didn't compress as much as was indicated on the paper. All in all, less than 80€ of material, spent a lot of time ago -and no money for newer stuff so here we go!