The official low-cost parking on the aiport is not really lowcost with prices starting at 3,50 EUR/day. I will fly to Scottland for a week and now I'm looking for a cheap/free parking near the airport. Are there any parkings within a walking distance or with airport transfer?

The official low-cost parking near Frankfurt-Hahn airport is not really low cost with prices starting at 3.50 EUR/day. I will fly to Scotland for a week and now I'm looking for an alternative cheap/free parking lot near the airport. Are there any parking lots within walking distance or with an airport transfer?