I'm a big believer that if you need someone else's money just to get something off the ground, it doesn't mean enough to you. I think people are too quick to give away all their work.
You've got a consulting income, which you admit you could increase if you take focus off your project. Is it a bad thing to do this if it means you remain self funded?
How long does $25K buy you? 3-4 months? What could you do in 1 month? Could you release? Why/Why not?
The lack a money is a wonderfully powerful constraint in proving your idea. It's better to force you product to confront the realties of the market it is in (i.e., is it going to float or will it sink) as fast as possible. Taking capital can sometimes delude you into believing answers to this question that aren't necessarily the correct ones. It gives you an inflated sense of positivity.
Good luck to you, either way!
I've looked through your comments, and I suppose you will take this investment. That's certainly your prerogative. I would say though that you should put all that money into releasing whatever you have now in some way or another. Kill whatever feature isn't done. Try to find an audience of potential customers that will be willing to help develop your software to finish. Some may even be willing to pay - you'd be surprised.
Also, it's fine to take "just money" rather than money with value add. As long as it's not dumb money.
There are probably millions of companies since the dawn of enterprise that took small amounts of money from friends and went on to be successful, often because of it.
Now, I don't know how much experience you have, but taking money from family is stupid. A) they are biased. B) the familiy member will always be there, for the rest of your/their lives. C) the debt, therefore, will always be in your/their minds, especially if the "investor" lucks out of other investments. D) 25K is easily gotten from other sources.
When people say "don't use your own money" I think this includes family too. I'd much rather use mine than families.
So my advice: keep consulting, take his advice and leave his money. If it's a good idea, there'll be no shortage of money from outside sources.
Just because there is a high failure rate doesn't mean the funding is not worth it for both parties.
If the plan to make money is good, it's easy to get money, so why risk it? It's already a huge risk without involving your family.
We have been doing consulting work primarily to stay in business at this point, but we need to cut it off or else we can't dedicated enough time to our project.
in regard to #3, this relative is an investor by trade. He has invested 150K this year in oil and natural gas, he is completely aware of the risk and is embracing it.
I definitely understand the strain that could still put, but I am not his first family investment, either.