I think the current AP costs (for zone progress) are fine - Wood and Stone have significant value now. Wood zones end up being more limited by total wood warmed over the gold cost of advancing, and mining depths are dictated by wood costs over AP. This allows for deeper progress to slow down unless people focus ascension points (and active play) towards these sub-systems over combat.
The only area that's a bit crazy for its costs would be the +max NRG upgrades for woodcutting/mining, it feels like it costs scale too fast for a linear +max NRG, which makes taking the +1 NRG regen option force more active play to net a benefit from it.
The only area that's a bit crazy for its costs would be the +max NRG upgrades for woodcutting/mining, it feels like it costs scale too fast for a linear +max NRG, which makes taking the +1 NRG regen option force more active play to net a benefit from it.