How many people died or got hurt from a DAC "explosion"? Probably not very many.
So is it worth the risk to buy an eBay DAC for a hundred bucks that has 500+USD worth of parts and a seemingly good assembly/design rivaling DACs that sell for upwards of 4000usd? I would say that unless you actually do have 4000usd to spend on a good DAC without it having much impact on your daily life, then no, it's not worth it to buy a cheap Chinese ebay one, but I for one am more interested in some bang for my buck (and if these are legitimate, they're the most bang for my buck I've ever seen in this hobby).
Personally I just bought a USB/SPDIF converter based on the XMOS chip for the price of that entire chinese DAC, so if these DACs perform well, they are interesting. Take a look at these:
They all seem to be quite good for the price.
I wouldn't buy any of these. They're all based on the weiliang pcb for the ES9018. Not only the pcb design is poor but they're famous to be loaded with fake parts, passive as well as opamps.
If going Chinese, the Matrix products seem decently engineered. The new mini-i pro especially.