This is what I’d buy if I lost all my equipment and had to start from scratch. Hope this is helpful to someone! The list is based 100% off of my contracts, clients’ needs, and my personal preferences, so make sure to not see this as a list to blindly follow.
Essentials (first things I’d try to re-purchase immediately)
Camera, lens, spare batteries
Laptop with card reader
Speedlight
Portable lighting kit (small light stand, umbrella bracket, small shoot-through umbrella, radio trigger)
Back-up solution for files (hard drives, cloud, etc.)
Next in order of priority
Larger light modifier (umbrella or softbox, for a softer light and larger groups and better shadow and contrast control)
5-in-1 reflector (that I’d only use for the black, white, diffuser options)
Second speedlight
Second light stand
Portable backdrop (reversible black/white)
Gels for speedlights
More sturdy light stand (like a C-stand with arm)
V-Flats
Backup equipment
More backdrop options
A bit more of a luxury
Additional lighting modifiers
Additional speedlights
Tripod
Continuous light
Larger light sources
etc.