[Ashbane]

I started doing 45 and 40 recently and can relate. I bought the Hornady classic single kit in Feb while supply for all gun supplies was very low. It took a few months with lots of backorder waiting but over the year had to buy in addition to the kit:

Lee 40 and 45 die sets, I chose the 4 die sets with FCD.
A pistol sized rotor/meter for the powder dispensor. The one that comes with it is suited for rifle.
Additional manuals, don't settle for just one source of data.
Powder based on reading from the manuals.
Used brass from MidwayUSA.com and other sources.
Primers from local stores to avoid online hazmat fees.
Bullets, plated are cheap local and got 500 free HP'S after about 5 months wait from Hornady.
Brake cleaner to clean all parts with, powder sticks to everything.
Tumbler, I made a rotating drum with corn cob media but there are cheap tumblers out there. I also bought the Hornady sonic cleaner as well and love it.
Primer pocket cleaner.
Deburr/chamfer tool.
Kinetic bullet puller.
Extra bushings for mounting additional dies in the press without unscrewing and reseting each one.
Dont forget your caliper measure!!!!

I'm starting to look at progressive presses. For the money I wish I'd have bought the hornady AP and just started slow with it rather than start with a single then go to progressive but I do like my single very much and will probably continue using it to deprime spent brass.

I also record every penny spent and every cartridge made/fired/bought in an Excel spreadsheet. I'd at least get a paper log to do this with. I've so far spent a total of $1500 over the course of the year on EVERYTHING but have also pumped out about 800 rounds included in that cost and I always have a couple hundred rounds ready for the range each weekend.