I have no experience with this mic, so I can't comment, other than to say there are several budget-priced tube mics out there. It might in fact sound great - I wouldn't know, but understand that just because a particular mic has a tube in it, that doesn't necessarily mean that it's a good sounding mic.

Maybe you could do a search for it on youtube, and see what others may feel about it, or, hear it in action ... although you should know that there have been videos from time to time, that have shown one mic being used ,while actually using another.

I would also do a search for any existing reviews on it, but stick with articles from the more-trusted publications - like SOS, or Tape Op, or Mix, as opposed to trusting reviews that are connected to promotional articles for it.

Here... I found the first one for you: http://www.soundonsound.com/sos/nov06/articles/maudiosputnik.htm

FWIW

Sometimes a drastic price drop is just a sale price, often times it's signaling the product being dropped from production, or the release of a newer updated version. In any case, someone is trying to reduce inventory. If you like what you hear in the demo samples and what you've read in reviews, this looks like a good time to buy one.

From Sound on Sound magazine:

Overall, I think this mic embodies most of the desirable characteristics of a classic tube model, without the attendant purchase or servicing costs. There are subjective variations between every make and model of microphone, but the Sputnik manages to strike a good balance between flattery and apparent tonal neutrality.

It's not a top-end microphone, but it looks good value at that price. Maybe you should get one before Thomann realise they have made a mistake.