No more than 30% for sure.

If you're paying 15% income tax (and by the way, you're probably paying no more than that, we earned over $150,000 last year and we paid about 14.5%).

But now I'm at the point where I have absolutely no more cash to invest so I'll have to start looking at other ways to fund the next few properties.I am really loathe to take out a mortgage because I hate the thought of paying someone else interest and I think origination fees are ridiculous.  

I invest in suburb towns around the Twin Cities, MN no more than a 45 minute commute to downtown and are all on the thoroughfare in the downtown areas of towns from 10k to 50k people.

Find a Hard money lender in your area or Private lender Very Easy to do, Find a 4 plex in your area very easy to do just make sure its in a good area to live, buy it at 50 of After Repair Value, refinance it at 65 ARV NO more then that" then keep doing this until you have 10 of them, (Just so vou know that's 40 units) Now after that PS you will be making great income by the way pull your funds together and purchase a 50 + unit apartment in a up a.id coming area. tnen your really going to like what happens after that...

It is a Fannie Mae and Freddie Mac guideline so all conventional lenders are going to require no more than 2% down.

I made back every cent I ever invested and got a return on my investment many times over.I have received phone calls from people who learn about me who have spent as much as $45,000 or more on "training", who knew no more about how to do a successful deal than before, begging me to partner with them.I don't know whom you are considering, but $30,000 seems a bit steep. 

Now, money per se doesn't seem to be an issue to me at this time , I know what I can get (up to $170K) and I know the interest I will most likely qualify for (no less than 12% for a start up with zero experience, but more likely around 13%-14% and no more than 15% for the first project).What I really look advise for is the marketing.

Would a realtor/investor typically invest outside of real-estate for a return on $25,000 investment, to make $75,000 in 60 days minimum to no more then 90 days?

The loan to value will generally be less than or no more than 75%.