You do not need a high-end FPGA; you need a bunch of small antennas (potentially extremely cheap, as these kinds of antennas are often microstrip antennae etche

You do not need a high-end FPGA; you need a bunch of small antennas (potentially extremely cheap, as these kinds of antennas are often microstrip antennae etched into PCBs), and a bunch of microwave-rated components such as mixers, phase-shifters and capacitors. The phase shifters allow you to add up the signals in such a way as to form a coherent beam in a certain direction, this is known as beamforming [0], and with some admittedly complex precalculation, an electronically-steerable antenna array needs nothing more than a simple microcontroller to set the phase shifters for the desired array orientation. Of course you would want to adaptively steer it based on received signal, but this can be done without the need for fancy FPGAs; your receiver signal chain will include all the mixers, demodulators and signal processing elements needed already baked in silicon; similar to how a WiFi chipset does channel adaptation by analyzing the received signal without resorting to high-end hardware, the kind of system that SpaceX is building does not require particularly exotic hardware (although it would be custom, and expensive to develop). Speaking of which, there's a neat project that sneaks into a particular Intel chipset and extracts the CSI (Channel State Information) from the wifi hardware so you can actually do things like estimate which frequencies are being attenuated [1]. It's out of date, but still shows the kind of live, complex, signal analysis that is possible with commodity-priced hardware. In short, I think it is certain that a base station can be built for <$1000, and likely that it can be built for <$150, although without knowing the precise specifications, it's hard to say. We did a case study on this in my antennas course in grad school 3-4 years ago, and our ending numbers on our prototype designs (not fully built and tested, of course, but simulated and spec'ed out with real-world pricing) were around $150. I am certain that our design as it was would not work, but something similar to it likely would. ;) [0] https://en.wikipedia.org/wiki/Beamforming https://en.wikipedia.org/wiki/Beamforming [1] https://dhalperi.github.io/linux-80211n-csitool/ https://dhalperi.github.io/linux-80211n-csitool/