If the TBS1052C were 40% off, that would be $306, which would make it a very cheap DSO, complete with Tek warranty and decent quality. That might make sense to someone outfitting an Electronics 101 lab or some other application where only very basic performance is needed, but commercial quality is wanted. And yes, the specs are miserable, but it is a perfectly functional device. I have a different Tek DSO with 2.5k memory and an antiquated feature set that is probably similar to the TBS1000 series, but it will still work 80% of the time for of what I need in the repair field.
However, the bang-for-buck hobbyist or economy-minded professional would not be interested in such an outdated relic. Anyone that has used a more modern DSO will be quite disappointed in these.