Roughly calculate €1500 for Spanish residents and €2500 for foreigners (also having in mind Power of Attorneys to delegate some of the work so you don't need to be here yourself) to set up the SL.

I'm happy to chat about the calculator I use when evaluating properties along with my set inputs.

In hindsight I can see all the mistakes I made but...pura vida.I do my proformas and try to calculate returns but I don't measure the value of investments purely on these terms like some others who've responded to you.

Make sure to research lenders, get pre-approved, and calculate your potential ROI before bidding. 

Here's a bit more in detail about how rates are calculated for DSCR loans:1.

BiggerPockets also has a calculator to analyze deals, and I highly recommend you start this as soon as possible, even if you are not ready to buy.

How do you calculate rehab cost given you can’t look inside? 

Quote from @Robert Quiroz: Quote from @Rick Albert: You have to keep in mind there is a calculation when it comes to increasing rents.On my last tenants of three years, I only increased once.

This is the form any lender should use to calculate you income (ignore the branding, it is the same for every lender):   https://www.biggerpockets.com/forums/49/topics/1224525-fha-l...You will see what you can add back from your 1120 based on the % of your ownership. 

I tried using the biggerpockets rental calculator this morning and the cashflow was negative, but I may have been too conservative with the numbers.