I purchased it for $405k and four years later I sold for $530k plus I had paid down the loan and kept that rent money. 

You can made money anywhere even counties with no growth even negative growth, but its easier where there is growth.

I wanted to consider trying this method and wanted to know this:If I borrow money from a lender, go in on a deal with renovations, how can I know if my Refi 6months to a year later will be enough to cover what was borrowed?

The towns are having to spend money on infrastructure, school, and general growth related headaches due to the population explosion.

Here are some options and considerations:Loan Against Equity/ETFs:Margin Loans:Description: Margin loans allow you to borrow money using your investments (such as stocks or ETFs) as collateral.Pros:You retain ownership of your investments.Generally quick access to funds.Interest rates can be relatively low compared to other types of loans.Cons:Your investments are used as collateral, so if their value declines significantly, you may face a margin call (requiring additional funds or securities).Interest rates can vary and may be higher than traditional loans depending on the lender and your creditworthiness.Securities-Based Line of Credit (SBLOC):Description: Similar to margin loans, SBLOCs use your securities (stocks, ETFs) as collateral, but they typically provide more flexibility and may not trigger margin calls as easily.Pros:Allows for ongoing access to funds as long as your collateral remains sufficient.Interest rates may be competitive.Cons:Similar risks of potential margin calls if the value of your securities drops significantly.Terms and interest rates can vary widely among lenders.Comparison with 401(k) Loans:401(k) Loans:Description: Borrowing from your 401(k) allows you to access funds without selling investments, using your retirement savings as collateral.Pros:Typically low interest rates.No credit check required.Interest paid on the loan goes back into your 401(k) account.Cons:Usually capped at a percentage of your vested balance (commonly up to 50% or $50,000).If you leave your job, the loan may need to be repaid immediately or could be considered a taxable distribution.Potential opportunity cost of missing out on market gains if funds are withdrawn from investments.Other Alternatives:Home Equity Line of Credit (HELOC):Description: If you own a home with equity, a HELOC allows you to borrow against that equity at typically lower interest rates than unsecured loans.Pros:Lower interest rates compared to other types of loans.Interest may be tax-deductible if used for home improvements (consult a tax advisor).Cons:Your home serves as collateral, so failure to repay could result in foreclosure.Personal Loans:Description: Unsecured personal loans can be used for various purposes, including investing, but typically have higher interest rates than loans secured by collateral.Pros:No collateral required.Funds can be used for any purpose.Cons:Higher interest rates and stricter eligibility criteria based on creditworthiness.I am a loan officer and we do some of the loans stated above.

What's the formula to determining how much money we are able to borrow?

It would take a lot of time, effort, and money to build something that multiple owners could agree on, and in the end it would save you 3%?

If you are looking for local private money lenders, you'll find them at local meetups.

I've been looking at land investing for a while and am finally saving up money to get started. 

Purchase price: $18,000 Cash invested: $245,000 Sale price: $335,000 New Consruction spec home built with the help of a hard money loan from Upright (Fund that Flip at the time). 1420 sqft, 3 bedroom, 2 bath home on 1.8 acres.