First of all, the best pricing I can find for black on black foam core is $5.60 at Michael's per 20" x 30" board, does this sound about right?
No idea on price, I have gotten pretty lucky and picked up some stuff for all sorts of prices. Check out the folding presentation boards (think science fair style) as well, they are frequently made out of foam core and are huge for the price (I have picked them up for ~$2 on a lucky grab).
For a T-Square, I found an Alumicolor 36" one (metal ruler, plastic T) at Hobby Lobby for $20 with an additional 40% off so $12 total. Is this considered fairly good quality? I'm not looking at getting a $60+ drafters square because I don't need that level of precision but I don't want it to be terribly off-square either haha.
I'm not at home but I think this is the exact one I use. It works great. Not the highest quality, but it is square. The depth of the plastic "T" part is thicker than most foamcore though, so you will have to use it on the edge of the cutting mat, which is honestly kind of nice since you can use it to line things up a bit better and get pressure where you want it.
Cutting mats are WAY more expensive than I thought! What makes a good mat besides self-healing? I imagine I want to get an 18x24 or a 24x36 right? What about "rotary cutting mats"? Never heard of those before I started shopping...Best I think I have found is a fiskars self healing 24"x36" at walmart for $30 (or they 18x24 for $17).
Jesus, they are so fucking expensive. WHY?! For my two cents, get the biggest one you can justify buying, your t-square is 36", might as well go for one that is at least 36" so you can use the full length.
As for blades, I have a utility pocket knife (trapezoid blades) like what you would find at home depot or lowes (the kind that fold out not slide), what is a good quality brand for blades?
I use this Gerber folding utility knife because I find it comfortable in my hand. This may still be the unpopular opinion, but when it comes to blades, I'm a quantity over quality kind of guy. You are going to be decimating them at a pretty good pace anyway and I haven't found the more expensive ones to last significantly longer enough to justify paying more.
Finally, where in the WORLD do I find black chipboard?? Everything I find is barely a step beyond construction paper and does not provide the rigidity I am looking for (2x heavy I think right?).
This is the hardest thing to find, in my opinion. Walk around Michael's or the craft store for a while and actually touch stuff and just go with whatever you find. I am kind of partial to framing matting, as it is super rigid and pretty easy to work with. It is, however, not cheap, and not usually black on black.
Not on your person.
I could carry the Victorinox and the box/bottle opener but definitely not the mini g
This is what's pretty much always in my pockets/hip. The black container has aspirin in it in case someone has symptoms of heart attack chewing aspirin can save someones life. Then there's a flashlight and a lighter.
The box/bottle opener normally lives on my work keys since I use it at work which I don't always have on me. Which is why I have another micro bottle opener on the aviation ring.
I forgot I often also have a Gerber EAB folding box cutter/money clip. But that niteize bottle/box opener isn't actually a cutting edge so I'll leave the count at 3 knives on my person. Plus an 18 tool multi tool that's in my backpack/car.
https://www.amazon.com/Gerber-Lite-Pocket-Knife-31-000345/dp/B002RILCLY
Even cheaper on Amazon. I really like this knife. Carry it ever day.