You can get all this stuff at your local hardware store, and none of it is very expensive, so you don't really have an excuse. I will say this: be sure to spend enough money to get comfortable gear. If it's uncomfortable, chances are you won't be wearing it when a cutter breaks or when some other nasty event occurs. But you probably already have much of this stuff lying around anyway.
Safety Glasses
Eyeglasses are the one thing you must have when doing metal work. Buy a halfway decent pair that are comfortable, because you will be wearing them for quite a while. The Home Depot cheap goggle type glasses get very uncomfortable after a few minutes. Shooting glasses work well.
Hearing Protection
As a shooter, I already own a few good pairs of comfortable earmuffs. It doesn't cost me anything to wear them when working around my power tools. It's a documented fact that moderately loud, constant noise will damage hearing. I don't mean to preach here, but it's cheap insurance.
Respirator
I use it when sandblasting (silicosis is a nasty disease that's easily avoided), painting, and working with other fume-inducing chemicals.
Gloves
Get a pack of nitrile gloves for working with chemicals; make sure they are nitrile. Quite a few solvents will soak right through your skin and cause cumulative nerve damage. Methanol in particular will cause blindness. Charming. More problems I don't need. Of course, using gloves while working with power tools is not a safe practice, but you probably already knew that.
Face Shield
Another form of cheap insurance, I wear it mainly when using my Dremel tool, bench grinder, or anything that throws sparks or fragments at a high speed. I also use it when working with chemicals; I don't trust my eyeglasses to protect me from a splash.
Apron
I have a plastic apron originally intended wearing for washing one's car. I think I paid $1.00 for it a few years ago, and it's been my best investment. Using a mill is a messy business, and you are guaranteed to get metal chips and cutting oil all over you at some point. I have a nylon pull-over shirt that I wear under it, it keeps my clothes clean and the chips don't stick to the tightly woven nylon. Also, loose sleeves can be a real hazard around a mill or lathe. Just something to keep in mind
Rubber Floor Mat
I have a set of interlocking rubber mats that I think I paid $8.00 for. Not only does it make it much more comfortable to stand on for hours at a time, but it has paid for itself several times over by saving my tools and work from damage when I drop them on the floor.