I've believed for a long time that it was impossible, since the AI will frequently tech it on turn 8, but it happens that, under some very special circumstances, it can be done.
What you need is:
1) Wang Kon (he's financial and starts with Mysticism)
2) A settling location that you can reach on turn 0 and that provides 3 Gold, with another 3 Gold in the first circle. For instance, 2 Freshwater Wines on plains will do (that's what I ended up with after some dozens of alt-Ging
)
Given that, you'll be producing 14 beakers on turn 0, which translate into 18 beakers when researching Meditation (I'm not completely sure why this is so, but I tested it) and you'll tech Meditation on turn 7.
Funny, isn't it ?
This may not be a great move, anyway, since a) you'll be working a 1F1H3C tile for the first 7 turns when (likely) producing your first worker b) foregoing the food techs for 7 turns is likely not a good idea... but still, you can ensure being the first to Buddhism without needing to take a gambit.
As a last note, I'm unsure of what happens if you tech Meditation on turn 8. If it works in the same way as the World Wonders, you *should* get the religion but I'm unsure about that. To get Meditation on turn 8, you would need to produce 16 beakers (modified value) per turn (*). I doubt that a non-financial leader can achieve that, but I may have missed something.
Cheers!
(*) or 4*15+4*16 since the cost of the tech is 124. But that doesn't change much to the fact that financial seems necessary.
What you need is:
1) Wang Kon (he's financial and starts with Mysticism)
2) A settling location that you can reach on turn 0 and that provides 3 Gold, with another 3 Gold in the first circle. For instance, 2 Freshwater Wines on plains will do (that's what I ended up with after some dozens of alt-Ging

Given that, you'll be producing 14 beakers on turn 0, which translate into 18 beakers when researching Meditation (I'm not completely sure why this is so, but I tested it) and you'll tech Meditation on turn 7.
Funny, isn't it ?
This may not be a great move, anyway, since a) you'll be working a 1F1H3C tile for the first 7 turns when (likely) producing your first worker b) foregoing the food techs for 7 turns is likely not a good idea... but still, you can ensure being the first to Buddhism without needing to take a gambit.
As a last note, I'm unsure of what happens if you tech Meditation on turn 8. If it works in the same way as the World Wonders, you *should* get the religion but I'm unsure about that. To get Meditation on turn 8, you would need to produce 16 beakers (modified value) per turn (*). I doubt that a non-financial leader can achieve that, but I may have missed something.
Cheers!
(*) or 4*15+4*16 since the cost of the tech is 124. But that doesn't change much to the fact that financial seems necessary.