Gadget Factory is a great source for reasonably-priced FPGA boards including the Papilio One which is currently US$38 with 250K gate Xilinx Spartan 3E. That's the best USA price I know of for a fairly large FPGA plus USB JTAG. Gadget Factory also has a 500K gate Papilio One (US$65) as well as a Spartan 6 LX9 Papilio Pro for US$85.
Today they began a Kickstarter for their new Papilio DUO FPGA/Arduino board:
https://www.kickstarter.com/projects/13588168/papilio-duo-drag-and-drop-fpga-circuit-lab-for-mak
Along with a Spartan 6 LX9, Papilio DUO includes an Arduino Leonardo clone with Atmel ATmega32U4. The board also has 512KB or 2MB SRAM, 64Mb SPI Flash, and an FTDI 2232H USB 2.0 communications chip for JTAG and serial communication with the FPGA.
The Kickstarter is an interesting read. It targets new FPGA users who are leery about having to learn a new language like Verilog or VHDL. Gadget Factory shows an approach using schematic editing as an easy way to get started with FPGAs.
Note: my only affiliation with Gadget Factory is as a happy customer who recently acquired a Papilio One 250K which I think is a great little board.