Vladimir,
An upgrade option is available. Go to
http://www.ni.com/upgrade/ and select 'Vision Software'. If you fill in your current version as 7.0, it will let you know the cost of upgrading to 7.1 which is significantly less than purchasing the full version again.
If you would like to speak to one of National Instruments technical sales representatives about various upgrade options call: (888) 280-7645