my .02, get a 1k with jjos on ebay, you can find one for like 5 or 6 hundo.
watch videos of the 1k, and watch videos of the 500...watch all of them. look up tutorials of chopping on the 500 and chopping on the 1k, see which one you like more.
watch tutorials on sequencing with the 500 vs sequencing with the 1k. be sure to look up grid edit mpc 1000 when you do the search, the 500 cant do this and i use grid edit all the time in my beats, its a nice feature to have.
i wouldent even consider a 1000 if it didnt have the 128mb RAM upgrade and jjos2xl.
if you think you can get by without the grid edit, and the chopping by waveform that the 1k will give you, go with the 500 and download a free program like audacity to chop your samples and drag and drop them in to your 500 via usb.
my first mpc was a 500, now i wish i would have gotten a 1k at first (this is what i have now) but after that i got the 2500, and a 1k, i recently sold the 2500 and kept the 1k, but now im thinking about maybe picking up a 500 if i can find one cheap on ebay this year or next year, although if i were just starting out i would just want to learn on a 1k.
the reason i now want a 500 is because of the portability factor, i want something small i can record sounds from my psp in when im traveling for work, i dont want to lug my 1k around for this, and the 500 doesnt have a HD in it, so i dont have to worry about that ever shitting the bed when i am traveling with it.
dont ever pay 1000 dollars for a mpc 1k thats new, buy a used one thats in good condition with upgrades and you can get it at a fraction of the cost, this goes for the 500 as well.
the machines arent built like shit, so if they have been taken care of they will last you along time, this is why i cant stress enough to buy a lightly used one.
i got my 1k off of ebay for 770 and it included jjos2xl, 128mb RAM upgrade, and a 160 gb HD, and i paid alot more than most people would have for it. ive seen similar ones go for 600 ish.
this is a video of the guy loading sounds he chopped in a free program on his computer into his mpc 500
http://www.youtube.com/watch?v=Jq4JA7V4ZB0there is some other good info on here about mono/poly overlaps (that the 500 or 1000 can do) and also about speeding up or slowing down the sample (that both mpc's can also do)
http://www.youtube.com/watch?v=Jq4JA7V4ZB0here is a video of someone chopping a sample on the mpc 1000 with jjos
http://www.youtube.com/watch?v=2a9NQZuPVgs