Have to get rid of the radon before I sell my home

I have had my eyes on a little beach shack for around 10 years. Finally, the beach house went for sale and my husband and I jumped on it. We have the beach house and need to sell our current home. Everything was going just perfect. The plumbing was all up to par. They put a blue dye in our water lines to prove that the septic system was not busted. They checked the electric and even the condition of the house. Everything was perfect until results came back that we had radon. Slightly too high of radon levels were in our basement. My husband and I were not happy with this. Because a real estate agent will not sell a house with above average radon levels and no one will take that house on. My husband and I had to spend 1000 on a radon mitigation system. We had the radon business in and they installed piping, a vent and fan that extended all the way to our attic. All of that time, effort and labor was to remove just a tiny bit of radon. The amount was barely above what was acceptable. Because of this though, my husband and I are worried that selling the house will be difficult. We had radon once, the house could get it again right? It might be red flag to people that the home already has radon mitigation. We really need to sell the place though, we can’t afford two houses. At this rate, we might need to give up our dream house.