And the Beagles only do digital-domain stuff, they won't get you an eye diagram or a bit error rate. Even for USB 2.0 that's quite expensive, the test fixture from Keysight¹ is about $800, the differential probe they recommend is the $11,000 N2752A², the oscilloscope in the minimum configuration that meets the >1.5GHz bandwidth requirement they sell is the DSOX6002A³ for $24,000, and you'll also need a software option license for the eye diagram testing option. Not to mention a PC to run the USB-IF compliance test software, but that's pocket change at this point in the spending.

Keep in mind that's just for the 480Mib/s USB 2.0. If you want to test USB 5Gbps, USB 10Gbps, USB 20Gbps, USB 40Gbps, or USB 80Gbps you'll be spending much more money. The USB4 V2 GEN4 Electrical Compliance Test Specification⁴ requires a 25GHz bandwidth realtime oscilloscope with ≥80Gs/s sample rate or better. Not to mention a ≥25.6Gbps pattern generator/BERT, 20GHz network analyzer, & RF signal generator, all of which are "call for quote" but likely to be in the 6-digit price range. You're easily looking at the better part of half a million dollars to test the 80Gbps cables fully.

¹https://www.keysight.com/us/en/product/E2667B/usb-2-0-hi-spe...

²https://www.keysight.com/us/en/product/N2752A/infiniimode-ac...

³https://www.keysight.com/us/en/products/oscilloscopes/bencht...

⁴https://www.usb.org/document-library/usb4-electrical-complia...