Really? Amazon provides many items, esp OEMs, at a reasonable price next to Costco and Home Depot. It is easy to see all the invoices/orders through web interface and printable any time for tax purposes.
My Amazon purchases are third in the rank, First Costco, then Home depot and then Amazon. Here is the history. This year, 2017, reduced order as my two kids started buying on their own. It is suppose to be around 200 orders !
2014 - 14 orders
2015 - 91 orders
2016 - 119 orders
2017 - 59 orders
Additional benefit is that we can see the feedback reviews and choose the best.
For example, when I want to select bluetooth accessories, I review multiple selections and choose the best out the group.
Same way, I came to know about Ubiquity network access point. Four years, I am using it, till date no issue.
Nest camera, best to get it from amazon at a cheaper price. Plenty of good reliable items at a cheaper price than elsewhere.