I believe this is exactly what's going on -- they're buying parts in bulk, often months in advance, and locking in deals that a single consumer can't easily go get on the open market right now.
Hardware pricing and availabilty pre-COVID was pretty predictable and stable, which meant the consumer could extract a meaningful cost advantage if they were willing to do the relatively modest amount of work of sourcing components individually and personally assembling the build. Right now, though, some places like Microcenter appear to have a cost advantage that fundamentally relies on market and pricing instability and can only be achieved through deeper integration with the supply chain and bulk purchasing in advance -- something a retailer like Microcenter can do, but I personally cannot.
Hardware pricing and availabilty pre-COVID was pretty predictable and stable, which meant the consumer could extract a meaningful cost advantage if they were willing to do the relatively modest amount of work of sourcing components individually and personally assembling the build. Right now, though, some places like Microcenter appear to have a cost advantage that fundamentally relies on market and pricing instability and can only be achieved through deeper integration with the supply chain and bulk purchasing in advance -- something a retailer like Microcenter can do, but I personally cannot.