rubber dome keyswitch
cherry mx red
i've used quite a few different types of keyswitches for long periods of time.... rubber dome, cherry mx blue, buckling spring, scissor switches and chiclet style and i've had the opporunity to play around with many others such as cherry mx red, black and browns. there is a definite difference between them.
i'll put it as plainly and simply as i can:
rubber dome keyboards can feel mushy. mechanical keyboards feel precise.
specific to cherry mx reds and blacks, they do not have key letoff so are comparable to keys sitting on springs. this gives a rather unique feel to them which many people like for gaming. rubber domes along with most other types of keyswitches including cherry blues and browns have key letoff which is where actuation force builds up until a certain level and the key bottoms out. on rubber dome keyboards this is caused by the rubber dome caving in. on buckling springs it is the spring bending. on cherry mx blue/browns it is the whole mechanism which generates this effect. key letoff is generally considered to be a positive thing for typing but some gamers do not like it.
if you plan on typing alot on the keyboard then you do not want reds. you want mx blues or browns as they are better suited for that task. for gaming often reds or blacks are suggested but you could use blues or browns if this will be a multi-use keyboard.
mechanical keyboards cost more for two reasons. 1) many mechanical keyboards are marketed as specialty type items or gaming items and as such people gladly pay the highly marked up prices... i mean the premium to have them. 2) they are more cost prohibitive to manufacture due to more moving parts so even the low end non-marked up solutions are not cheap. 3) the switches are made by a cherry which then distributes them to the other manufacturers at a set price. since all manufacturing is not in house they cannot save in this regard. this can be good for quality control but bad for prices. of course there are other brands like topre and ibm/unicomp however you specifically mentioned cherry.
you can get a cherry mx blue keyboard for $80 over at mechanicalkeyboards dot com. ducky zero to be exact. another low cost alternative is a unicomp classic which uses buckling springs and is also $80 and is a remake of what is considered perhaps the best keyboard ever made. its also perhaps the loudest keyboard ever made which turns all but diehard fans (i admit that i am one of them) away.