Typically this is what you can take to high net worth people and discuss it with them to help back you. That means you will instantly have 1 or more partners,

Typically this is what you can take to high net worth people and discuss it with them to help back you. That means you will instantly have 1 or more partners, but it is doable. Couple of other options, Leveraged Buy Out, where you purchase his business over the period of say 1 year, during which time you guys split the net income. These are tough to get right and have everyone see it as a win-win, sometimes you give up 2-3 years of 50% net income, plus a 25-75% down payment. The more amount of money you put in the better deal you get. A lot of small businesses are sold this way, just not talked about a lot in the tech circles. Combination of things, bank loan, home equity, friends and family and maybe 1 or 2 high net worth people. Again, you wind up with lots of details to work through. Last option, if you like this client, you could always try and partner with him. OR cut a deal that says you will bring his product to market in another industry and you want 75% of net income on it. You can even rebrand the product sometimes if the client is willing. He may see it as a win-win as he doesn't have all the risk to enter a new market, plus gets your attention to make sure things are running tip-top. Remember its net income, so he'd still pay you for upkeep of the current product within the market he is currently in. But new features or rebranding would be on you for the other market.