Pricing for jet cards varies by provider and by the size of aircraft. Some providers quote prices that include fuel fees and others quote prices that exclude fuel fees so make sure to ask about all aspects so that you are comparing apples to apples. See this article for a detailed comparison of jet cards and all the factors to consider.
The major fractional providers and large fleet operators, such as NetJets and Flexjet, provide time on their own fleets to their jet card holders. So generally with these companies you'll be flying on an aircraft that they own, manage and control. They also tend to be newer aircraft. The charter companies jet card holders fly on aircraft selected by the charter company, but these companies typically do not own or operate their own aircraft.
For a typical 25 hour jetcard on a light jet the prices are in the range of $120,000 to $150,00 range. For example the Air Partner price for 25 hours on a light jet is $132,500 including FET and fuel, with additional discounts available for return trips or older aircraft. NetJets price on the Phenom 300 starts at about $172,000 and this includes fuel fees but excludes any fuel surcharges or FET.
At NetJets a 25 hour jet card on a Citation Latitude starts at about $210,000 plus FET and any fuel surcharges need to be added. At Flight Options a 25 hour jet card on a Citation X is $170,500 plus FET and all fuel charges. Air Partner charges $162,500 for 25 hours on their JetCard Sterling (somewhat older aircraft) or $177,500 on their model year 2000 or newer aircraft. Both of these include FET and all fuel charges.
NetJets price for 25 hours on a Gulfstream G450 is about $365,900 and includes basic fuel charges, but FET and any fuel surcharges are extra. Sentient Jet has an hourly price of $14,013 for heavy aircraft in their "Preferred" program and includes FET and fuel surcharges.
In comparing any jet card pricing, make sure you are comparing apples to apples. Different providers include or exclude different charges in the main, headline prices they quote. Other features may also differ from provider to provider, including the age and type of the aircraft.