"There is no reason really to buy this software any longer. "
Actually, there is still at least one reason that I can think of to buy the software: Ability to use third party data/datafeeds. TS 2000i, like prior versions, does allow you to use data from a variety of sources/formats, or even, if you're so inclined, to use synthetic data. For people interested in doing certain kinds of backtesting and research, this capacity is critical. TS6 works only with the TS datafeed. Similarly, if you're already using, and happy with, one or another trading platform and data vendor (whose data can be employed with 2000i), but you wanted to be able to employ custom indicators or backtest signals, again, you might want to use 2000i.
With the sole exception of the data limitations, TS6 does remain, however, a superior product in most respects, in my opinion, especially for trading: It's more stable, offers more features, works faster, and doesn't rely on that cumbersome "Global Server" for acquiring and maintaining data.