Okay, for reloading, you have the following tasks
1) decap/resize
2) trim the case to length (rifle/bottlenecked cartridges)
3) prime
4) bell
5) charge (i.e. put the powder in it)
6) seat the bullet
7) crimp
step 2 is usually done off the press (dillon 1050 is an exception)
many presses combine steps 4 and 5 into one station.
3 is usually done on the upstroke with one of the stations.
For discussions sake, lets say all that is done with a total of 4 dies.
With a single stage, to make one loaded cartridge, you have to pull the handle 4 times, and swap dies 4 times. So with a single stage, you usually batch load. Which means if you are making 100 rounds, you decap and resize 100 cases, prime the 100 cases, swap dies, bell and charge 100 cases, swap dies, and seat 100 cases, swap dies and prime 100 cases. LOTS of handle pulling. For pistol, it absolutely sucks. For rifle, where you have to trim the cases and very often trickle charge powder to the exact weight, and shoot much less of it per hour, it's not necessarily a bad choice. What you need to do to get really accurate rifle ammo benefits form the workflow to some extent.
With a turret, you put all the dies in one toolhead, and you CAN do all your steps in order on each round of ammunition. So basically put in brass, pull handle to resize, prime on the upstroke, advanve the toolhead to the belling die, pull the handle to bell, etc. SO basically in the 4 die example, you pull and advnace 4 times for each loaded round. However, on something like the lee turret, the priming function is so awful, I chose to batch resize and prime, then do the rest of it like normal. DOing that, I could get up to 100 rounds per hour. Still very tedious. Some turrets are auto advanceing, but I find that I trust manual more to avoid mistakes.
Then there is progressive. Where once you get fully under way, there is one piece of brass in each station, and each pull of the handle makes one round of loaded ammunition. This can get you up to the neighborhood of 300-400 rounds of ammunition and hour without a case feeder. Add a case feeder, and you cna get up to about 600 an hour. Some progressive presses are manual advancing, but I trust automatic advancing presses more to avoid mistakes.
As for price vs. quality, I'd avoid that RCBS kit. Best bang for the buck IMO if the lee 4 hole turret kit, but deactivate the auto advance (which really means just don't put it in when assembling the press), and get a hand primer, as it's teeter totter priming arm SUCKS.
If you are shooting 300-400 a week, get a progressive. There's no point screwing aorund with anything less. While you are getting the hang of things, you might only run one round through at a time to keep things simpler. Hell, if you can afford 300 a week, you can probably afford to get two dillon 650s, one for large primer and one for small primer. Then it's jsut swap out toolheads.