I reckon you need to "upgrade" some of your gears before proceeding to A3 and A4.
If you find you can't solo in A3/A4, go play in co-op game.
You need a group of players with determination.
I played at public game in A3/A4 (until Prime Evil). I met a group of players with full determination.
In A3, I had a monk and a DH (with high DPS). Monk & Barb are excellent combo when it comes to melee (both need to select the right skills).
In A4, I was the only melee hero and there were very good Witch Doctor and Wizard in my group. We played with full determination despite being killed like toufu in A4. Those flying elites that rained fire meteor were the pain-in-the-ass. There were few occasions we met few packs of elites and champions at the same location. We just kept whacking & whacking.
If my memory serves me right, I spent 500-600K of gold on repairs in A4.
In short, you need FULL determination if you play in co-op in A3/A4.
Each player must know the role to play and NEVER give up in whacking the elites (no matter how many of them).
Being killed like toufu is just normal - unless you have god-like gears.
Haha.. I get what u mean. Some player just quit When killed couple of times.
Yup. Plan to get some upgrades. Gt outbid by others player at last minutes. 900k ring then I put 3mil at last minutes. Still too low. I guess the fella put 10 mil at less then 1 minutes duration. Haha..