At the cost of 350k, it's quite a lot and I would have to borrow about 200k.

Quote from @Jen Whitehead:  My husband and I have two properties that we used second home loans and in both cases my lender knows that we also rent out to help cover the costs.

Take a look at the list and keep in mind that increases are based on what they used to be priced at (growth) not at relative cost to each other.

Especially nowadays with the cost of capital so high it makes even more sense to cause you're getting 4-5% to hold it, and not having to loan it at 10% when you're stuck. 

Lots of cost most of us would not have considered.  

If I want to replace what’s already there (in very bad condition) it’ll cost $12k.

Let's say we we bought the proporty for $600K, sell the property for $1M , say a morgage of $400K was pending at the time of selling, say $80K is closing cost, say we spend $50K for rennovation before selling.  1.

Make sure you are accurately calculating your holding costs. 

Then figure out (in today's dollars) what it will cost to replace.

What's the purchase price and estimated rehab cost as a % of ARV?