Everything else in this game feels fair to farm. You can farm frags in PvP, you can farm gear in missions, skill points and XP are abundant… but cash is just a big roadblock on letting us progress our heroes.
I currently have 47/59 heroes but I find myself only playing about 15 of them, at most, because I simply can’t spare any cash to play the others and get their skills up. The PvP system (matchmaking) will also punish you if you bring in underskilled heroes, so all they do every do is serve as patrol and gauntlet 1-2 fodder. I’ve also stopped evolving heroes I don’t need for the same reason - they eat up cash but don’t provide many benefits.
Missions give negligible amounts of cash, using my entire stamina/energy reserves gets me enough to raise one higher level skill. Every hour of energy will get you about $4k… which is nothing. There’s also PvP and the crates give a decent amount of cash, but the drop rate is so low (6%) that you have to win close to 100 games just to see a single cash drop.
Lastly, you have the Gold —> Cash transfer. The first transfer is actually decent, 10g for the cash you get is not a bad deal, but at 20g on average you’re basically paying a quarter’s worth of gold to raise a high level skill once. That isn’t an awful deal for your best heroes, but for everyone else who doesn’t see much play, I would never spent real money to get someone like Francoise’s skills maxed - and since PvP punishes you for not maxing skills, they become almost unusable except as a throwaway slot.
This becomes a predictable cycle, HHG doesn’t give us much cash because they want us to pay gold for it - but they also give us dozens of heroes that each take millions and millions of cash to max out for skills/gear crafting/evolution. So we’re forced to just spend the cash on the “good” heroes and let everyone else gather dust. Either we need more cash from events/PvP/missions, or HHG needs to reduce the cost of skills, because nobody has an incentive to experiment with off-meta heroes if it takes away days and days of cash that we could be using on our best team.