I've had similar thoughts, if they introduced Flower Pots as a 1x1 item in private rooms, it wouldn't interfere with the economics involved in crossbreeding... since if the number of full gardens exploded then the prices for things obtained through hybridization would just get shot to hell like what happened with soldiery mats. And having a garden is how people who have invested in a house can recoup their investment. But letting people grow their individual seeds would actually open up new markets... if I get a result from crossbreeding like a minion seed or something else but I'm growing Thavnairian onions, it might just end up stagnation in the FC chest because the cost/benefit to growing it isn't there for me... but if others who don't have it can plant it (or a Chocobo coloring seed from allied seals, or krakka root seed, etc) in a single flower pot in their private room, what's the harm? Someone using a full garden at a house to grow these items is underutilizing their garden anyway.