@Yooni Choi managing from out of state (OOS) with ZERO previous landlord experience - probably won't go well.You WILL make a lot of mistakes that will cost you money.

It is my understanding that the new owner will have the house at the cost basis of my purchase price, for calculating capital gains taxes or depreciation.For gift tax purposes for you - FMV.For capital gain tax purposes for the recipient - your original basis/purchase price 

Is there any good rules of thumb to estimating the cost of a boiler?

@Vincent WeselakIt’s a good idea to get an estimate for your insurance costs upfront since this can vary based on the property type and location, and it’s a key factor in evaluating your cash flow. 

What should it cost?

It's an opportunity cost, just like anything else.

I would need to put $45,000 down upfront, with a monthly payment of about $650.

Obviously it will cost money, get some quotes.

Since rental losses are typically passive, the best way to offset W-2 income is through Real Estate Professional Status (REPS) (750+ hours) or Short-Term Rentals (STRs) (100+ hours and more time than anyone else managing the property), which allow real estate losses, including depreciation, to offset active income.A cost segregation study accelerates depreciation, generating large upfront deductions.

@Kerry Baird Love hearing about others taking advantage of cost segregation studies.