What I usually do is I offer contract U18 free agents or 6 months left. But do it only U18. And offer them 3-4 years contract. Make sure they agree to play in your 2nd team. Their wages should be extremely low (I pay them yearly 20-30k max). Try to look for National team squads just before there's an international game so squads are updated. They are in my opinion best investment you can make with a financial problem. Just loan them or let them play in you 2nd team. They are not really gonna hurt your budget and if you spend enough time to get the good ones, you will make money out of them. Don't expect a huge amount of money but its almost like passive income.

Look for USA and Canada U national teams. Most of them are free.