fasttech.com is legitimate. I've ordered from them several times although shipping can take a while.
As for the juice, I'd pass. All of the hangsen juices I've ordered are passable in terms of taste, but they don't vape well. I ended up throwing them out because they would combust, leaving a soot behind in my toppers. Yuck.
If you want super cheap eliquid, I'd invest in some basic mixing equipment, nic base, usp pg/vg and then get into simple DIY recipes.