My starting hero spends the early part of most games looting ruins. So, before turn 10 I often find myself with 1500-2500 gold. Back when I was playing Darklords, I would rarely spend this gold on unit production...preferring to horde it until a hero with some impressive allies showed up. However, playing beta 3, I find myself buying expensive units instead. Why? Here are a few reasons....
1)Beta 3 heroes are weaklings. Compared to Darklords (or even beta 2) heroes, beta 3 heroes take quite a while to become anything remotely impressive. The decent abilities cost many levels worth of xp, and the cheap abilities aren't worth having.
2)Beta 3 heroes don't bring much in the way of allies. My best hero offer to date was 2 demons or 1 devil (depending on what you prefer)...and I could have bought devil production for the hero's hiring price.
3)Allies aren't all that. An elemental? A medusa? They are good in their own way, but they are very slow, and I prefer my heroes to be more mobile. A wizard? Its a 2 turn unit for a reason. None of these are 'must have' units for me.
4)Must have units. There are units I need, and if I don't find cities that produce them fairly early on, then I am forced to buy them. They are...Pegasi, battering ram/catapult, and Unicorns. Most of the allies accompanying heroes are not nearly as useful.
5)No quests/No ruin allies/No items. Heroes can't quest (like they could in Darklords) which makes them inherently less valuable. They can't get allies in ruins..so the allies they bring are all they will ever directly obtain...and the lack of items means they always have to take the hard road to self improvement.