> (they're also dramatically less expensive)

It depends, but for typical networking I'd say Ubiquti is actually offering better pricing here (outside of 10G LR) - and I'm saying that as someone who has sold 10s of thousands of FS modules to customers.

             |  FS  | Ubiquiti
  -----------+------+-----------
  Programmer | $369 | $49
  10G SR     | $25  | $12 ($20)
  10G LR     | $34  | $59 ($85)
  25G SR     | $49  | $29 ($49)
  25G LR     | $74  | $69 ($119)
  100G SR4   | $99  | $39 ($69)

Note: Prices in () are the costs outside of the limited time mark-down period.

Side note for the HN crowd: For ridiculous homelab 100G shenanigans look for Intel 100G-CWDM4 on sites like Ebay. They go for $4 and work with SM LC fiber from 0-2000 meter runs, making great DAC replacements (cheaper+thinner replaceable cabling). They run great, I've had 8 going for a year. Even if all 8 failed tomorrow and I bought 8 more that's still cheaper than a single 100G SR4 from FS. You can pair these with used 100G NICs for ~$100, making a 100G direct connection between 2 machines ~$250 after shipping+tax.