I was still waiting on comments from:
[size=150]Strawberries of Magical Power[/size]
This patch of strawberries grew on the grave of a powerful hedge wizard. Each year in the spring, three overly large and perfect strawberries grow on it that contain Creo vis. The leaves of those berries can be harvested for Corpus vis. This is a cutting of an original plant that is more productive. The plants are kept in a bit of soil that has one of the hedge wizard's leg bones in it. A local legend says that eating the other berries from the patch fresh increases a woman's chance of having a child. And it is reputed that a wine made of older, fermented berries from the patch can prevent pregnancy.
Provides: 3 Cr vis/year and 3 Co vis/year, both in the spring.
Costs 30 BP
[size=150]Skull of the Parted Lover[/size]
Tales tell of a faithful maiden whose true love died while on crusade. The maiden stayed faithful to him and cried for him every night. She died decades ago, but her skull continues to cry for him. On the feast of St. Martin of Tours, the day her lover left for the crusade, her tears contain Mentem vis.
Provides: 3 Me vis/year in the autumn.
Costs 15 BP
I was also going to propose a remote source in the hills outside of Thessaloniki:
[size=150]Cave of Gaia's Tears[/size]
One of the hills outside of Thessaloniki is reputed to be where the titan Gaia came when Ouranos took and swallowed their first child. She was said to have wept bitterly for the loss, and her tears soaked into the hillside. Whether this is true or not is anyone's guess. But in a cave in the hill, beneath where Gaia is supposed to have wept, a stalactite forms at a shocking rate of several inches per year. The stalactite is always covered in water that is reputed to be the remnants of the tears of Gaia, still dripping to this very day.
The stalactite can be harvested once every six months for a pawn of Terram vis (or once a year for two pawns of Te). If the water that drips from the stalactite is collected, it amounts to two pawns of Aq vis per year.
The covenant has sealed off the part of the cave that has the stalactite so that no one will wander in. They have a wand that will open a temporary passage into the cave that the vis can be harvested.
Provides: 2 Te vis/year and 2 Aq vis/year, traditionally harvested in summer.
Costs 20 BP
Wand of the Doorway Through Stone
ReTe 20
R: Touch, D: Mom, T: Part
When this rune-carved wand touches stone and the wielder speaks a command word, up to ten cubic paces of the stone appears to melt and move as the wielder directs. A Finesse check is required to do anything fancy with the stone. The covenant uses this wand to open a doorway into the Cave of Gaia's Tears so that vis can be harvested, and then to seal the cave up again.
(Base 3, +1M Touch, +1M Stone, +1M Part, +1M Size +5 uses/day: 24)
Costs 8 BP