I'm curious if experienced investors have a ballpark percentage they factor that rents will increase, on average, over the long-term (like 30 years)?

-Charge an option fee 3-5% to get some cash-in-hand.

-I am quoted a higher interest rate and more fees since its a rehab loan. 

I've included an example below to help illustrate this.So different lenders have different rates (which do vary even for DSCR loans) but these are factors they all consider.See example below:DSCR < 1Principal + Interest = $1,700Taxes = $350, Insurance = $100, Association Dues = $50Total PITIA = $2200Rent = $2000DSCR = Rent/PITIA = 2000/2200 = 0.91Since the DSCR is 0.91, we know the expenses are greater than the income of the property.DSCR >1Principal + Interest = $1,500Taxes = $250, Insurance = $100, Association Dues = $25Total PITIA = $1875 Rent = $2300DSCR = Rent/PITIA = 2300/1875 = 1.23DSCR lenders generally let you vest either individually or as an LLC.

However, the rents have not caught up to the increase in house prices which are making the metrics impossible to factor.

I also need some other “soft” costs (origination fees, etc.) taken care of to get the deals going for each deal. 

Factor in things like credit health, de­bt load, and financing options.

Last thing I would suggest is if you decide to go solar I recommend paying cash to save money on all the loan fees.

For quickie emergencies there are always the "18 months no interest" options at Lowes or Home Depot along with similar terms from your credit cards (those checks you can write for a 3% fee and then have 12-18 mos to repay). 

Hey Aaron,If the goal is to use the HELOC as a down payment for a DSCR loan, you will also need to factor the Prepayment penalty when you decide to cash out on the new appraised value after all renovations are completed.