Agreed, My current bow is this amazing bow I picked up for 5k. It had a socket so I went and looked at a few other auctions for a ruby and bought an item with a square ruby in it for like 5k. Just crafting it from the radiants (I believe radiant is right below square?) costs around 5k I believe, not to mention the jewelcrafting stuff you need and the level of jewelcrafting required which costs money to reach.
I think just about any class soloing a difficulty above nightmare will be hard. I'm currently soloing the rest of Act 4 on nightmare and some enemies are just a huge pain. Though, DH has a skill to stun so on single enemies, it's a lot easier. Most of the bosses can barely move. Use 2 1handed crossbows that both add attack speed and some rings and other pieces that add attack speed. Get to like 3.5-4.5 attacks per second and he's constantly stunned. Unfortunately that doesn't work on larger groups. You could do cluster shot + the stun rune but that uses a lot of hatred. You could also add preperation + punishment rune + the passive to reduce discipline consumption so you can get a good 3-4 full hatred bars in a row without having to wait and that can stun large groups. Though, you can easily get swarmed from 2 directions which makes this tactic useless. Act 3 was incredibly difficult for me because I play with a Witch Doctor friend and he focuses more on HP and his tank zombie which has like 30k+hp, allowing me to just pump out my damage with equips that don't focus on vitality, but trying to solo those phasebeasts that teleport around and swarm you from 2+ directions was almost impossible with my tactics and equips.
I've been enjoying the auction house a lot.
I'm currently level 47 and my damage is at 4k (the damage stat). I played the auction house well, looking for amazing gear and cheap items with good gems on them, then reselling it for more after I've had my use of it.
If anyone wants to play, my battletag is "GL1TCH3D#1864"
Level 47 DH on Nightmare difficulty act 4. I'll probably finish nightmare by tonight.
Currently saving up to get an amazing end-game bow.