I started out back in about 1975 or so with a simple "Lee Loader" on my kitchen table. If you are not familiar, a "Lee Loader" is a really inexpensive reloading kit in a box about 4"x6"x2". Everything you need is in there. They are caliber specific, as included in the kit is a sizing die, a spoon to pour the powder in, a de-capping pin, and a bushing to set each case in whilst you work on it. Extremely slow and tedious, and smacking a round in and out of a die with a plastic mallet is usually "distressing " to your significant other and neighbors. Not a happenin" thing. I was doing about 50 rounds of .45 ACP a night after work.
Next up is a single stage press. I suppose a guy could bolt it firmly to a piece of 3/4" plywood ( doubled up in thickness for rigidity) and maybe clamp it to a table---maybe---- but probably also not a happenin" thing. With a single stage, you can switch calibers, and if you plan on only maybe a 100 or so at a whack, it wouldn't be too bad. You will need a bunch of other related items, such as a powder measure, a scale, reloading case blocks, some specific tools ( calipers, wrenches, etc), maybe a case trimmer, and a few other things I am sure I am forgetting. A little faster, but it will occupy a considerable amount of real estate. A pain in your grommet if you will have to tear down the entire set-up every time you are NOT reloading.
Next might be a turret press. All it really is is a single stage press with the capability to spin a turret that already has the numerous dies you have mounted. It speeds thing up a noticeable amount. No real difference in the amount of space required compared to a single stage.
Then I guess the next step up would be a progressive press. A whole lot faster, a whole lot more going on at one time, a whole lot more to concentrate on at one time. Again, not really any more space, but reloading isn't really a thing you can set-up and tear down time after time, as much as I hate to say it.
Cost? Well, that's the big question. As expected, the more you buy in bulk the more you will save per unit, but the more you will spend outright. I buy by the pallet load, and get stuff really cheap compared to going down to Sportsman's Whorehouse and buying components off the shelf. Sure, I am technically "saving" money-but only compared to buying things in much smaller quantities. I have over the years kinda figured if a guy has a source for brass, unless he really wants to get into the reloading hobby, it MIGHT be better to simply scrap the brass and use that money for buck ammo. Which brings up another option-- in certain calibers, it is almost cheaper to buy bulk ammo rather than reload when you factor in everything!
.308 and similar sized rounds require a goodly amount of horsepower when re-sizing, so clamping it to a kitchen table for example might put you over what the host table was designed to withstand- after sizing a few hundred. (That is the voice of experience speaking!)
I am currently sporting 4 progressives, 3 turrets, and 4 single stage presses, and have about 450,000 loaded rounds on hand. NOTHING is more calming and relaxing than going out into the shed, crank up some Boston, and load a couple thousand rounds.
Am I saving money?