Q: noticed that sockfancy.com is using shopify? is there a way to set things up like they do: user checks off the options they want and then they go directly to a single-page checkout for their subscription?
A: A subscription is a recurring order. For recurring orders they are using Recurring Orders & Subscription Box App by Bold, and Recurring Orders Enterprise, which is only available to Shopify Plus merchants.
Q: how about the single page checkout?
A: The single page checkout is also a feature of Shopify Plus plan, which starts at $2000 per month. They are also using cashier by Bold.
Q: It looks like those Bold plugins add commission costs of about 3% or more per sale?
A: I don't know the details of that, but again they are available only for Shopify Plus.
Yes it's true that you can set up a generic site cheaply, but for a site that actually works well and has single page checkout, etc. you get into some very big bucks, and also some very large sales commissions.
Fully Loaded Time - 7.8s
Not sure anyone would think this is an acceptable amount of time to wait for a page to load.
Taking a quick glance, it looks like Privy and Zendesk/Zopim are the main culprits. That can be easily fixed - just don't use those apps or find alternatives that don't slow down your site.
Shopify is competing with any other shopping cart software, and for companies concerned with performance there may be a case for hosting your own.
How many of them have better performance? Might just be a "all of you have to do is be faster than the slowest."