So I ended up having a little bit of an exchange on social media yesterday about when the break-even point might come with respect to constructing new garrisons. I had done a little bit of analysis last year to determine how long it took to break-even on a garrison in pure gold terms, but that analysis assumed an unlimited amount of time. (And by the way, as a quick refresher, that analysis showed that it took 21 days of operating with a fully built out garrison and slate of followers to recover the approximately 10,500g investment for fully building it out).
So just to level set, here is what I'm generally looking at in terms of a fully stocked garrison for gold-making. It is a level 3 garrison, a level 3 inn (for the treasure hunter missions) a level 3 salvage yard and a level 1 trading post. It is also a full slate of 20 followers with the ones with specific i-level requirements for particular gold missions geared to those points. Note that you could increase that to 25 followers with a level 3 barracks, but the cost of doing that in both gold and garrison resources would be higher, and it's not going to change the answer at this point. The cost of building that out is approximately 10,500g and 3,550 garrison resources.
Now, if I'm leveling a toon from scratch, I am typically finishing up that process with around 1,000 garrison resources (that assumes that I'm using them to buy experience potions from my garrison quartermaster as I go).
So now it comes down to how long it would potentially take me to get to that break-even point. One of the gating items is how long it would actually take to accumulate the garrison resources to fully build out the garrison. At 2,550 net garrison resources needed, and an accumulation rate of 144 resources per day, that works out to 17 days, or just slightly under 3 weeks. You could speed this up by building a lumber yard, but this would take quite a bit of extra time every day on that character to go out and collect the lumber, and at this point, that's not a time investment I'm willing to make. You can of course feel free to choose differently. In my case, my next max level character is going to be my 23rd 100, so I've got less willingness to invest additional time in those alts.
So between building, and then accumulating gold, that brings us to 6 weeks total. The real gating item from a time perspective is accumulating the followers. I am typically finishing the leveling process with somewhere between 9 and 10 followers, just from working through the typical leveling process. I am not generally going out of my way while leveling to collect specific open world followers because generally those followers do not have the traits that I'm looking for - which are scavenging and treasure hunting.
So using my inn to recruit one follower per week, it is going to take me at least 10 weeks to pull together the full slate of treasure hunters. Now the three week time frame to accumulate the garrison resources to fully build out your garrison runs simultaneously with this, and you will be accumulating some gold while you are recruiting those followers, but not enough to make a significant dent in the break-even calculation. It will likely also take you at least a week to fully level those 20 followers to max once you have your full slate of 20 collected, unless you're doing nothing but garrison mission for this particular toon.
So if I assume it takes 10 weeks to accumulate the followers and then 3 weeks to break-even on the gold (assuming the gold accumulated while recruiting helps to offset the additional time needed to level those followers to max), you're at a minimum of 13 weeks to break-even, which from today, puts you at July 29th. So if you think 7.0 is going to drop on or before July 29th, it is likely too late to break even on a new maxed out garrison at this point.
What I would recommend instead, is to go ahead and upgrade your garrison to level 2, and build out a level 2 salvage yard, a level 1 trading post and a level 2 inn (or conversely, don't worry about the inn and just head out into the world and grab some followers), continue to accumulate garrison resources to use at the trading post and sell, and then do whatever base gold missions you can. The cost of doing that is only 2,800 gold with the level 2 inn and only 1,350 gold if you ignore the inn, so is much more likely to be profitable over the next few months until launch.