Once mortgage is denied seller is left high and dry, 30 days and sometimes 6 months into the contract (sometimes even longer, in cases where seller is a builder who built the whole $700K mansion for you, in firm belief that your bank will come through and finance the entire purchase at the end).

To thrive in real estate investing, you must maintain a firm grip on your finances.

Also, would you suggest using professional firms to do the hiring process or should I do on my own to save money?

A few things you could consider:House Rules: Make sure you have clear, firm house rules for your STR guests regarding noise levels, shared spaces, and respecting the privacy of your LTR tenants.Noise-cancelling measures: You could invest in things like soundproofing the walls or adding landscaping (like thick bushes) along the privacy fence to further dampen any noise between units.Separate Access: If possible, ensure that the STR and LTR tenants have separate entrances or parking areas.

I've told him no multiple times, that I'm firm on the agreed upon price since he had time ample time for due diligence and if he wants lower, then I want to void the cancel the sales agreement so that I can put it back on market. 

Our firm has found great value in that.

If you're looking for an accountant / book keeper reach out and I have an excellent referral for a firm that is virtual, does only real estate investing, and their accounting work is incredible. 

Ty so much for such a thoughtful and knowledgeable answer. we are pretty close on the purchase deal terms and will start marketing our group of 10+1 duplexes just as soon as we have a firm deal.

On the other hand, many large firms have a minimum charge they will stick you with and still give you a template form. 

When working with Civil Engineering, Is it best to simple pick on firm and go with them, Or is the 3 quote rule in effect at this stage of the process?