MoC Armlet PT MoM
Also known as the "Cheapskate" build. Basically, you build those four items at like 15 minutes, and start killing everyone. Nobody will expect it and you have mad sustain with lifesteal and armlet toggling. You reduce armor with Medallion of Courage so you hit really hard (deso level hard), you turn armlet on for 40 bounus damage which scales with your crit, you get PTs for more attack speed/dps and you turn on MoM for huge attack speed boost so your crits are basically guaranteed. At 15-20 minutes if you have this, literally nobody will survive it. You'll have a ton of armor and HP should you need it (armlet + MoC), you have evasion for more survivability, you're only going to be pretty prone to getting stunned/nuked down, which, if you're worried about, should be remedied by a BKB. It should seem sad that the most expensive item you have in your inventory is BKB, but it's fine, you can continue to murder people.
Hopefully you'll be able to get 1200 + 2320 + 1400 + 1800 = 6720 gold for this as soon as possible (with standard gold per second, it boils down to around 130 last hits), but even if you don't, with just MoC and PT you can actually kill people and start farming heroes to improve your snowballing tempo. You aren't AFK farming, waiting for your next item to come, you farm the lane, and start farming heroes as soon as you see you have the DPS to do it.