You must be more fortunate or better at looking. T5s come up all the time for cheap; the last two I bought were $50 and $100, but every time I look for a toploader it's closer to $600 for something I have no idea how well it works and I'd have to pay to ship it across the country. I've never, ever found a toploader for sale locally. Not to say they aren't out there, but I've never seen one.
It's been 4-5 years since I found those three, but all were bought in less than a year's time. Ain't looked for one lately. All the T-5's I have noticed were in the $300-500 range.
I've never done a deal with any due to the fact I cannot tell the good from the bad in these. I never took the time to learn their ins and outs in Id'ing them