Lazada, just like Amazon, destroys the livelihood of the locals, who are probably struggling and making sacrifices to even send their kids to school. I never use them.
As far as bargaining, if it is a reasonable price I pay it. If it's inflated, I question it.
What may be 50 cents to me, might be the difference between feeding the family or sending kids to school for the seller.
I've seen them set up every day and pack up every night ... 7 days a week in many cases. You really want to talk them down to your cheap-as price? How about a little respect for how they exist?