Well back when I had my original TP, the keyboard went out on it. Sprint store offered me a Moment, some BB, or the TP2. I took the TP2... This was more than a year ago now.
If you lose it, that's not insured directly thru Sprint - you have to pay a deductible and a 3rd party (Asurion) actually does the replacement.
AFAIK the fee is now $100 for "Advanced" phone replacements (IE any 'smart'phone).