Hey ,

... how many logic gates can I get for one US dollar.

... how much NAND/NOR gates, or transistors can I buy?

There are several problems associated with this:

• Modern FPGAs do not have that many 'logic gates' anymore, because they got replaced with Lookup Tables (LUTs) which can function as a single logic gate but also as a complex network of logic gates.
• A lot of elements in an FPGA are not logic gates (or LUTs) but could be built from logic gates like for example Flip Flops (FFs) or Block RAMs (BRAMs) or Digital Signal Processing Slices (DSPs), or the routing fabric.
• The basic elements in FPGAs or ASICs are transistors and capacitors, so that's probably the better unit but FPGAs can be easily adapted to your purpose while ASICs need to be designed and produced, so there it really depends on the volume.

I've read somewhere that the average transistor price in 2000 was 1 microdollar and roughly every 4-5 years the decimal place needs to be adjusted by adding one more zero. So it would be about 0.1 nano-dollar by now or about 10 billion transistors.

The Semiconductor Industry Association (SIA) 2005 Report claims that the total cost per bit of DRAM memory is 1 nano-dollar, so that would be at least 1 billion transistors per dollar in 2005 which matches the above.

On the other hand, Wikipedia claims (from Xilinx sources) that the Virtex-7 2000T, which comes at a hefty price of 18k USD, contains 'only' 6.8 billion transistors, which gives about 400.000 transistors per USD.

Conclusion: for one USD you'll end up somewhere between 400.000 transistors (or 10.000 gates) and 10 billion (or roughly a billion ASIC gates).

Hope this helps,

Herbert