When I was in school, there used to be, what I thought, was a pizzeria down the street from my apartment which I never went to. One day, I decided to give it a go since all the other pizza places where chains and I wanted something fresh. I walk in and all the pizzas where fully ready to bake but raw. They sold raw fully assembled pizzas for you to take home and bake yourself which in itself isn't that bad but, they charged $24 for a cheese pizza so, essentially, you're paying premium price to do some of the work and NO convenience. I feel that buying a walmart bike and adding all these parts, taking time out of your life to shop for them, put them on, buy the tools to do so is a very similar comparison to the pizza. You get no convenience, you still wind up paying big money, but in this case, you're funding a huge corporation that turns a profit by not paying it's employees, suppliers, and paying back into the tax pool. No offense but that's not really a bike I'd be proud of.
I bought my bike from a small local bike shop, paid my sales tax, utilized a local employee to assist my purchase, and now I buy many accessories from this nice local store and I intend to keep it that way. Food for thought.