The Black Magic Pocket, the one sage linked to, is $995.
It's a micro four thirds mount, with a (almost) super 16mm sensor. If you couple the camera with a metabones speed booster (the one specific for the black magic pocket camera) not only will you get a boost of like 1.5 stops of light, but it's also a focal reducer. Which, in the simplest terms means it will behave as if the camera's sensor is a Super35mm.. which means wider angle shots, etc.
Of course there are a good deal of extra bits and bobs you'd want to acquire for it as well.. namely ND filters and a good IR cut filter, or NDIR filters. The black magic cameras are very sensitive to IR, and your image will quickly become poluted with IR radiation (haze with a red/magenta color shift) especially with higher ND filter values.
That can all be added as you go, of course, but good ND filtration is going to be pretty much necessary regardless of camera if you want shallower depth of field (one of the many reasons people go the DSLR route in the first place).
So, with the extra about $500 for the speedbooster, and probably $500 of filters, yeah realistically you're looking at close to $2k for the black magic pocket camera. Of course you _can_ go more bare bones with it, just the camera and a single lens.
With the t4i or t5i or any other t[something]i, you're going to need either some kind of audio breakout box/preamp (juiced link, beachtek, etc) or a separate audio recorder.. same with the black magic cameras. Many of the options in the ebay results I linked earlier have dual XLR inputs, and would (at least initially) eliminate that need.
Along with the other audio gear -- good mic(s), boom, etc.
Then of course there's the concerns of adequate lighting, camera support gear (tripod, shoulder mount?, jib?, dolly?).... costs add up quick when you start buying gear, that is why a lot of people still advocate renting.
There's so much more to it than how many pixels they squeeze onto the sensor of a camera, etc. If you're going to jump into gear ownership, it's best to have as complete a view as you can beforehand.. I think.
And really, there's no sense splurging on a great camera if you're going to starve it of light, and record crap audio. But, if you're going to splurge on a great camera, considering the size of the investment, you should probably either A) figure out how to make the camera pay for itself, and/or B) get the best camera you can afford that will be useful to you for several years.
B is the reason I'm buying the new black magic 4k. I absolutely don't need 4k right now. But I also don't plan on wanting to upgrade again in the next 5ish years, and I shouldn't need to. Also it's got a global shutter which is really just kind of bad ass.
