There have been instances where I have successfully closed deals by putting down as little as $100, while in other cases, I have chosen to deposit $4,000.

I'm sure someone here has chosen a smaller one and can share their experience? 

(different loans have different seasoning periods for your funds and different guidelines on allowing gifted funds - something to consider) To determine closing costs you can call a local title company in your chosen area and ask them for their fee sheet and your lender should be able to provide you with any other fees associated with the loan.

Consider your goals and how your chosen passive income stream can help you achieve them.

As for me I’ll bypass rules and evaluate each deal independently to see if it fits criteria I choice which I’ve chosen to provide the best shot at reaching my goals.  

@Monir BadeerI would not recommend doing this unless you are going to go to your chosen market in person to build your team

So now with your $70k (from HELOC and selling Crypto) you have enough for a $280k house (75% LTV). 

Third step, decide what kind of strategy you want & can apply to your chosen properties & locations.

I’ve got $20k in reserves in a high yield savings account, plus the usual mix of speculative crypto and blue chip IRA. 

Investing in Syndications, Funds, Joint Ventures as Passive Investor - Limited returns but carefully chosen a portfolio can ROI at 12%.