They were supposed to bill based on hours (different rates for framers, drywallers, supervisors, etc.), and send me invoices every week.However, they never sent me the invoices each week, and when I asked about the overall cost of the project toward the end of may (the project started in May), they told me $35,000 so far.

But the risk is that should the deal go south (check out what happened to real estate values in 2008-2012) the investors may sue you for selling an unregistered security without an exemption from registration and since you did not utilize a Reg D offering you would have no statutory defense. 

Hi Nicholas, thanks for the answer and let me provide more details :) The offer is to invest into new construction with 20%-30% down payment 0% interest rate loan till the end of the construction.

They are a smaller organization but also offer landlord services. 

This will be subordinate to the existing FHA loan, but you’ll need to qualify based on your credit score, income, and debt-to-income ratio.Home Equity Line of Credit (HELOC): A HELOC could also be an option, offering flexibility in how you draw and repay funds, though it might come with variable interest rates.Balloon Payment Loan: This type of loan can offer lower initial payments with a large lump sum due at the end of the term.

Any recommendations for lenders who can offer 90% LTV for buying secondary/vacation home?

This can be a temporary solution until you find more favorable financing options.Private Lenders and Hard Money Loans:Alternative Financing: Private lenders and hard money lenders may be more willing to offer loans secured by your mobile home portfolio.

instead i have amazing surprises.I'm thinking of offering a class to share my experience and offer advice to others.Thoughts?

These are generally business loans based on assets and income of the property often structured as DSCR (Debt Service Coverage Ratio) loans.

Even if newer buildings can't price rents as low as yours, they might offer amenities or modern designs that attract potential tenants.Local Economic Factors: Consider local employment rates, major employers relocating, or any changes in the local economy that might impact rental demand.2.