Junos on a 48 port PoE+ switch for the price of a nice dinner. If you want to learn enterprise networking on real gear, this is the cheapest legitimate entry point. It is end of life, it is loud, and it draws real power, but the software is the same Junos running in production networks everywhere.
Across 28 listings tracked in the last three days, the median total cost in USD including shipping is $147, and the lowest is $70. RackSniper flags a listing once it falls at or below 70 percent of the trailing 30 day median, which for this product means roughly $103 or less. Condition and configuration vary widely on used enterprise hardware, so treat the median as a reference point rather than a target.