OK there is more than a bit of tension between shopping and saving.
How can you save and spend at the same time?
I will let you solve these contradictions.
In some cases, I like these more focused sites as you might have a better chance to find quickly what you are looking for.
One example of that is Bountii which helps you find the best prices on Electronics and Small Appliances.
I just discovered the site so I cannot affirm that they offer the full range of products and sellers at the best price.
What I can say is that Bountii home page is uncluttered and makes for a quick read.
Feel free to share other niche search engines with me, in the US and abroad.