That can definitely happen, especially when getting into high performance stuff or scale. I spent 2 years building my Corsair and was so nervous to fly it the first few flights due to knowing how much I had wrapped up in it. She is a very docile flyer though and lands sweet with full flaps.
Now, helicopters,.. PWEW! I had a .30 size heli with a scale Bell fuselage on it (see attached),... Between that and the Corsair, I could have paid for my PP Certificate but who's counting......
Like GA, you dont' want to tally up the costs in RC either.....