This is what I did about this bug:
on includes/estate.class.php
around line 224
I changed:
$this->estate_price = float($_POST['estate_price']);
$this->estate_rent = float($_POST['estate_rent']);

for:
$this->estate_price = $_POST['estate_price'];
$this->estate_rent = $_POST['estate_rent'];

and that solved the problem so far. I don't know if there's a better solution out there, however has been working for me.

Cheers.