Personally I like my planes built to fly, not to crash.
So in answer to your questions:
- Do you crash a lot? ..... Not much
- Do you wish your plane was stronger?... Nope, that would inevitably mean it was heavier than it needed to be, so with less performance and actually more likely to crash.
- Would you pay more for a crash-proof plane?... Nope
- Do you have any experience with crash-proofing?.... Not as such. I've strengthened weak points on airframes, like landing gear, but I've never attempted to design or build a plane primarily with crashing in mind.
Of course this is just my view. Of course a 'crash resistant' plane would be good for a beginner providing the weight impact was minimal. If you have been flying for a while and still crash a lot then IMHO you are doing something badly wrong and you need to look at why you keep crashing, not the 'crash-proofness' of your plane.
Each to their own, good luck with your venture.