Rob your neighbour and sell all THEIR stuff on eBay so there's no initial outlay of any kind. Also, if you happen to find a pedigree dog whilst rifling through their home, start doing that con trick with the dog in a bar. Double score.
Oooooooh it's an invisible signature... oooooooooh!!
I believe Nietzsche put it best when he said 'YER MAW'
Even better, Rob their stuff, wait for them to get suitably depressed about it, then sell THEIR stuff back to them at a small cost. Actual profit and instant gratification.
About as reliable as dice. Schizophrenic dice.