This game is quite fun (at times) but if you want to make ANY progress you need to be willing to pay. Buying a top tier premium pack on Dale will set you back about $35 and then you have 100+ hours of working out how the hell ro fly your new premium. In this state you are a 'wallet warrior' your teammates will hate you for your incompetence but you will in tern come yo hate the wallet warriors yourself.
That being said I have maxed out my US and USSR tech trees for the small price of $130 and 1.3k hours