It really depends who your connects are. A fina kit really makes life a lot easier though because you know its 100% real and potent because you make it yourself. Buying 50 cc's of tren from some guy at the gym will cost you a shitload of money. The only truly expensive stuff (assuming your not getting ripped off) is exotic shit like GH and exotic roids like Primobolan injectables ( which isn't made by that many companies anymore).
I haven't juiced in almost 5 years, but back then I remember the hardest and most expensive shit to get was post cycle therapy stuff like nolva, clomid, etc.