I've bought from a loca B&M and will definitely do so again, I've also bought from online vendors in the US and will do so again, and I've bought from FT and will probably do so again. I buy my juice locally or from a US vendor that makes it, gear I usually shop around for good prices but unless it's something big I will trade a few dollars for getting it faster(from US vs China). But let's take my one and only FT purchase as an example, I bought the vamo kit, with two extra battery holders it came to $50.39 for the vamo, two Panasonic 18650 batteries, and a nitecore i2 charger. If I had bought that same setup from my usual gear vendor, who is usually pretty reasonable anyway, it would have been at least $70 and they don't carry the i2 charger, it would have been a cheaper one. Now, if I would have bought this same setup at my local B&M, well, They want $60 for the vamo itself so it'd be close to $100 at least.
I vape on a budget, I had planned on waiting to get a vamo, since I had just spent $35 last month on an ego twist, yeah, you read that right. But I couldn't pass up a great deal, and if it hadn't already been linked to everywhere I would have spammed that link as well. Supporting the local economy is great, supporting us vendors is great, saving $50 that you can then spend on something else locally(locally grown food for instance) while getting the great vaping gear you really wanted, that's fantastic.
Last note, what makes you think that any of the money you spend at a "local" online retailer STAYS local?