I think we’ve all underestimated JakeSuper! – This is his site, right?
Problem with a site like that (or Kyero) that come from the English-speaking world, is a lot of properties on the market won’t be listed.
If looking for poor (and dirt-poor) places you get a lot more to peruse by using Idealista. For instance, if looking for dirt poor properties in Murcia, select the area (and choose max 60k) but then select order by the cheapest first (baratos primero):
Even on page 6 you are still looking at properties on sale for just 28kEuros (£22k)