You can't currently purchase 7.2 - you rent it at $199/month use-only; $99/month brokerage included or; $0/month (minimum 250,000 shares/month traded). All data feeds included, but I don't believe exchange fees are included.
Don't use either at the moment, but am in the same boat - shopping around, comparing prices and facilities.
I'm not sure that there is a large difference between 2000i and v7 when it comes to the programming language. A major difference is in using 2000i you can select from a variety of data suppliers (Tenfore, Esignal, etc.) whereas for v7 you have to take Tradestation as your data supplier, which doesn't seem to include European markets. (The 29K (euros) software is some sort of artifical intelligence, neural net type trading software)
The 29K euro (Safir XP) software is some sort of add-on as far as I can see. Someone has written something that works with TS2000i indicator sets (must be something sensational for that much money!!). Tradestation provides the platform on which to develop systems through a programming language. There are a lot of programs written for Tradestation that are available on the web (not sure if any of them are any good though - I have used Tradestation 2000i to write my own systems and to test strategies and ideas, which is the main reason to have the software).
I think the choice of whether to go v7 or 2000i should be based on the following:
1. Do you want to rent at $199 per month or own outright at around $2500?
2. Is the data you want available with Tradestation.com (v7) - if you need data that they don't supply you may need 2000i and another datafeed. (Although I think that there is an interface available for v7 to pull in other data - take a look at http://www.tssupport.com/ )?
3. Do you need a link directly to a broker (which Tradestation has with v7) or can you code your own API to use with a different broker (such as IB) so that you can automate order entry?
4. Is the historical data available on v7? I use historical data from Tickdata Inc. which will run with 2000i.