Other posters have already answered that temple cost is going to be fixed in the next patch.
Man is a strong nation. Though a forest nation like Pangaea, and with some points in contact with them (nature magics, stealth in the mix, etc.) they play differently. For once they have strong air magics and their longbows are roughly 3 times cheaper than the Pangea archer - and you know what this means: massive squads of longbows backed by wind guide. In later stages of the game, you can unleash a powerful barrage of air magics. Air/Nature has some cross-path rits/items that are very interesting: rainbow armour, amphiptere, etc. Their bards are great, with insane stealth and able to instill uprisings. A mass of them can bring down an economy to its knees. Crones are brittle, prone to old-age afflictions and relatively expensive, but get in the habit of buying one per turn and be sure they can wreak havoc in the battlefield - air magics is very powerful. Even Mothers (recruitable everywhere and only 130g) can pull out some nifty tricks. Man's songs are more effective than Pangaea's - but prolly not much more
- and though Pangaea's sacreds are stronger, IMHO, the wardens are nothing to sneer at.
The dom wizards around here, can tell you more tricks to pull with Man, but it's a pretty decent nation.
Note: Mother of Tuathas is another unique pretender for Man although I do not think it is cost effective - a shame really, as I happen to like her a lot.