Market Value Updates are offered twice a year, every January and July. Updates are completely optional and you buy them only when you want. Cost is $10 per database and special discounts are offered if you buy updates for several countries or subscribe to them. We are planning shortly to allow people to purchase and download updates via internet.
No, Coin Elite never erases you information. The market value updates simply puts in a new file containing the new coins and values. If you upgrade your program your old information is converted into the new formats.