I mean how long does it take to earn those 30k for a token?
The tokens have not actually been 30k gold since the first day, they usually flip between 20 and 25k throughout the day (usually going down to 20k in the early morning hours).
Anyway this is a hard question to answer without knowing your experience with WoD (so forgive me if I am saying obvious things you already know). It is very fast and easy to whip up 20k gold right now without ever partaking in your server economy but not immediately, it requires setup. Your garrison with a max rank Inn unlocks follower missions that reward gold. In addition it lets you recruit followers that have an ability that doubles the gold you get on a mission and this ability stacks (so a 3 person mission will give 3x the gold if you have 3 followers with said ability).
This takes a while to set up because you can only recruit 1 follower per week and rerolling follower abilities is unreliable, but, when you get it going you are looking at a bunch of gold per week for basically no effort (turning in a bunch of follower missions and sending them back out takes like 2 minutes tops and these missions take a few hours to complete). I am doing this on my alts who are still in the process of leveling and gearing followers but each week each alt generates ~5k gold for my main right now. Even if you only do this on one character it will give a bunch of gold, plenty enough to buy 1 token per month if you supplement it with other methods (such as the below one)
Past that raids are your best bet, Cataclysm 25 man heroic bosses drop ~125g per boss plus the loot you can vendor. If you do every Cata raid this is around 3500g at a minimum BEFORE vendoring any drops (realistically it is much more because the dropped items vendor for a lot, 2h weapons around almost 50g per for example). Downside is you need somewhat decent gear to run 25H cata raids. Full LFR gear is probably enough but that can take a bit to get, though, not nearly as long as building up your follower roster. Even in good gear clearing all the raids can take a few hours but considering the weekly lockout it's not actually a terribly huge time investment and you can get stuff like mounts/transmog if you care about those things.
Wrath raids are still decent money too (better than gathering professions for time vs. gold made) but I usually don't mess with them since they are less gold than Cata raids and take more time to run because the sheer size of the raids and how much walking is required (ToC being the one exception obviously).
Of course obviously stuff like professions will still make money but those 2 methods are worth mentioning since they do not involve your server economy or anything, it is just generating gold out of thin air. Unless Blizzard nerfs them (which personally I am expecting by the end of the expansion) they are incredibly reliable ways to make a bunch of gold per week.
Hopefully that helped a bit but like I said I don't know the current state of your characters which will pretty dramatically impact how fast you can get to making gold. But the tldr simple answer to your question is: making enough gold for a token each month is piss easy right now if you are willing to put in effort and a rather minimal time investment. It only snowballs if you are willing to level alts to level 100 and do follower missions on them (which as mentioned is not a big time investment once you actually get things setup).