If you know what you wanted to buy, you can actually get it cheaper sometimes from 11street or gemfive. You will need to check who (shop) is supplying the goods, they will provide the warranty.
While 11street is middle man, you can actually contact the seller to find out who they are. While many might be individual sellers, there are also plenty of traditional and reputable brick and mortar sellers there too.
Most on-line site provide protection to both buyer and seller. Delays for refund is inevitable as there is a minimum of 2 weeks to one month as the payment chain is long : on-line site -> payment gateway -> credit card -> seller . If you are worried about shipping delays and damages, you can always arrange to self-collect and get refund from shipping (not always possible).
For example, Desa Home sells both on 11Street and GemFive platform though may not always offer the same price. According to them, prices there is the same as retail. There are also plenty of sellers trying to sell at extremely inflated prices as well.
Sometimes there will be promotions offered by these on-line platform that is not provided by the seller. It is possible to get additional discount ranging from 10%-25% that the seller would otherwise not be able to provide. One good example is IT products. We all know most IT products (mainly DIY components) only offer small discount but if you buy them on-line during a promotion, you can actually save quite a bit.
I'm not saying that it is all bed of roses here, but what I'm saying is you just have to be careful just as you would when buying from traditional shops! I bet you won't want to buy from non-reputable shops even if it is cheap.
I am not saying don't buy from online websites but try not to buy electronic items (especially expensive ones). You can imagine the trouble you're going to get when you get a faulty one.