To minimize the cost and time of learning VHDL for FPGA design you could follow these steps:
1. Download from Aldec their free multimedia VHDL tutorial EVITA.
2. Read guide to synthesis with VHDL. These kinds of guides are available for free from most synthesizers vendors. For example, you could use guide from Leonardo Spectrum at www.mentor.com.
3. Download Xilinx Free Webpack from www.xilinx.com.
4. I would suggest to buy not Virtex, but Spartan2E based board. This IC is just a cheap version of VirtexE with the same set of features. It is possible to find development board with this kind of IC in the 100 $ range. Check Elektroda for links of producers.
As a assignment to start with I would suggest to design simple microprocessor. Just divide it by simple blocks and try to implement them step by step. For example, you could start with multiplexer design, then re-design it to support any length operands. Then try to implement adder, full Alu, control FSM and so on.
Here at Elektroda there are a lot of very experienced guys. Just ask questions -anybody will definetely help you in your process!
may use a project like xsoc from jan gray, leon from galiser or openrisc soc by opencores.
working with a project will push you to learn and u will have a clear target.. such as making the processor works, making the sdram controller works, making the serial port works... adding a AMBA devices... etc..
of coz, you will need a lot of materials, books, questions to this board to help you in the process.