I worked as an IT Manager, and a COO as well for SME tech companies and agencies, so based on my experience you can have a salary between 300-600.000 HUF net per month. This is approximately 1000-2000€ net. It really depends on your knowledge and the sector that you are targeting. At big telco companies or banks, you can get more, but the work is less interesting.
Hungary is a very bubble-headed country. 1,7 million people live in Budapest and only 200 thousand in the second biggest city. So expect much better opportunities in the capital than in the countryside. Bigger cities that you can look after are Szeged, Debrecen, Miskolc, Pécs, Győr.
Regarding your question, if Hungarian is a hard language to learn or not - it is very hard. But I know many foreigners who have learned it and able to speak at a good enough level over a couple of years.
Good luck, and let me know if you have any further question