So the OP is asking about round wound TI strings and everyone is posting the merits of their flats. OK.

These are completely different sounds and comparing the life of flats to rounds is a non starter conversation. I can't EVER tell when flats are dead because
they are pretty much always dead. No one who is after a round wound sound will be buying flats for the savings or in lieu of. Its a completely different product.
The TI flats are great. The TI double bass strings are great. The round wounds are nothing special and when I used the 3 or so sets mine died just as fast as anything else out there. The sound and feel was fine the longevity was less than Pro Steels and Sadowsky Blacks. There would be a possible market for used flats of a specific character. Rounds would be weird as you lost everything the string would be wanted for. Unless you want dead rounds which are easy enough to collect without paying for them.