While I'm a fan of Slickdeals, that's just the normal EDU price.
That said, the $100 does seem much more significant on the base model than it does on the other preconfigured models.
For the Mini and iMac, it's pretty much a flat $100 off any model. Individual upgrades are typically about 10% less than retail, but I noticed that this is not the case with the non-pro M4 Mini. If you want want to bump the RAM or storage, EDU doesn't get any discount on the first tier upgrades (such as 256GB to 512GB) and only a 5% discount when going from 256GB to 1TB. Understandable when the base model is so attractively priced, but you can see how they are squeezing all they can from those choosing to upgrade.