Thank you for the quick reply.
I have two major E-bay concerns.
1. Shady people. (They just suck.)
2. Shady items. (Extremely low quality items are usually hard to use and inaccurate, which hinders use and causes new adopters to dislike the equipment/approach/hobby.)
pH meters are that bad? I suppose I can pick up some strips until I decide if I want to fork money for a quality digital meter. (I have used some very nice hand-held digital meters in the past, but I bet they were rather pricey.)
I've seen the stir-plate tutorials, and have a freshly broken hard-drive at work I suppose I could salvage. I bet I have a 12V fan with at least one broken blade I could use too - just dremel off the remaining blades to re-balance/reduce drag...