I was in your shoes not so long ago. I had the bucks for a used Inspire, but needed to save more money for a brand new model. I almost bought used and then I happened to see a You Tube video of a guy fishing his out of the water! Even if it ran OK, (which I seriously doubt), after it was dried out, how long before water damage caused something else to fail. I don't think there are any extraneous extra parts on most quality drones. Everything serves a purpose. In other words if another part failed, you are likely to end up with an expensive paper weight.
As for Ftolino, I am guessing he meant you could part a damaged Inspire out someplace like eBay. Certain pieces are always in demand to repair someone else's damaged Inspire.
I will leave you with this little story. I purchased a RC helicopter-used-off eBay many years ago. Paid a fair price, but when I got it I could tell it had been abused. I couldn't get my money back and ended up spending twice the price of a new model just to get it to safe flying status. The thing never did fly right , so I took it all apart and sold the pieces. Did get half my investment back.
The final decision is yours to make. For myself, I will never buy used RC type aircraft again. Almost impossible to tell exactly what it has been through.