It might prevent drafts in very old windows but there are better and less expensive methods. 

@Brett Leavitt This is amazing, I really need to figure out my local market soon to see how i can best apply this method.  

I do like your buy & hold strategy, but unless you really enjoy driving to tenants to collect rent every week, you should consider requiring your tenants to sign up for automatic withdrawal from a checking or savings account.Collecting rents in cash creates the opportunity for payment disputes, not to mention being a security risk and a huge inconvenience for you.If you're goal is to build a serious portfolio of properties, you'll need to resolve the rent payment issue sooner or later.

Go with the Reverend @Lucas Carl method. 

It's best for the seller and provides them more security.

If you do move forward with an offer I would also see if you can get the security deposit transferred to an escrow account held under an LLC you form for the property.

Now we've begun to consider the idea of real estate investing via the method of live-in flipping or a live-in flip - BRRR hybrid method. 

I'm open to most methods of investing but plan long term to pick up buy and hold properties (if the market is friendly for it).

Cash buyer's list has grown beyond my primitive "cut-and-paste" methods. 

However, I am worried that the only way I can secure financing for any type of flip would be dependent upon the salary that my corporate job (which I am desperately trying to leave) provides me.