BCAA products.
I'm guessing the main benefit of Leukic comes from it containing leucine, an amino acid. It lowers cortisol, prevents fatigue during workouts, and helps protein synthesis. It's just that Leukic is way overpriced, in my mind.
Xtend is a good product.
Purple Wraath is also a nice amino acid mix, but the last version tasted terrible. When I get money, I'll probably be trying the new version.
Or you could just go for bulk BCAAs to try to cut cost.