Even working as a scientist, I buy equipment from eBay. If you bide your time, you can find useful bargains. In fact, even when my budget can accommodate new ge

Even working as a scientist, I buy equipment from eBay. If you bide your time, you can find useful bargains. In fact, even when my budget can accommodate new gear, there can be exceptionally long lead times, whereas an eBay seller has it on hand and will ship it out tomorrow. This makes it harder to copy a documented design, of course, but most of the time a scientist with a knack for gear can adapt things as easily as copying them. Also, people did photon counting for a long time without 50 MHz ADC's, just saying. ;-)