CONTAINS BIG ****ING SPOILERS, DUDE
How can you make a horror movie with no money? Well, one option is to make a regular movie but skimp on all the things that would have made it any good - get some friends and work colleagues to act in it for a laugh rather than hiring real actors, if you know someone in a band then get them to do the music, camcorders are cheap, and you can do the mutant piranha, octopus, locust or meerkat effects with relatively inexpensive (albeit rubbish) CGI. Alternatively, you can look at your resources - for example six performers, one location, two cars - and create something that you can actually afford to do. Whether the finished product stands or falls will then be more down to your actual filmmaking abilities rather than the result of a tiny budget badly spent, because while any idiot can make Mega Piranha for whatever tiny amount of money was spent on it, even Spielberg, Zemeckis or Soderbergh couldn't make it any good for that price.
13 Hours In A Warehouse has just six main speaking parts, three apparitions, two cars and apart from some opening exteriors, all takes place in one location - the warehouse. Five crooks steal a priceless artwork from a gallery, intending to sell it back for a cut of the commission paid out to the recoverer, but the operation doesn't go entirely as planned and they end up with a hostage. While they hole up overnight in a deserted warehouse owned by two of the crooks (they're brothers), it soon transpires that they are not alone: the numbers 32369 appear on the wall in blood and elsewhere, strange noises echo round the building and someone (or something) is hanging dead rats in nooses in a side room like some warped animal snuff theatre.
What do the numbers mean? Did something unspeakable happen in this place years ago? While the hoods banter about the film career of Robin Williams (in what writer/director Dav Kaufman clearly intends as an echo of Reservoir Dogs' famous discussion of Like A Virgin) and plan to secretly double-cross each other, three strange supernatural figures bump them off in interesting ways. Their appearances are probably the best thing about the film: they have a genuinely creepy videotape look to them as if they're copied off a battered old VHS tape, and the first sight of one of these figures is a superbly timed "boo!" moment. One scene looks like it's trying to emulate Sadako crawling out of the TV set in Ringu, but (amusingly) she's coming out of a gents toilet instead. On the flipside, the characters are pretty unlikeable (except for the hostage, who's just a blank) and it drags in the talky scenes.
Result: a just about effective enough horror film that's absolutely no great shakes, but has clearly been made within its limitations, rather than ignoring the limitations then pleading budgetary deficiency as an excuse for why it's crap. None of the victims are remotely worth giving a damn about - they are foul-mouthed murderous crooks - and it isn't dazzlingly well acted or written, but the horror scenes are well enough done for the film to just about get by, and it's got a good creepy location and some good effects work with the spectral figures. That's more or less all it has going for it: it is borderline okay, but don't expect any kind of masterwork.