Inexpensive Tube Amps

You get what you pay for. Some Chinese gear can be good, but amps at this price range will be riding the very bottom of the barrel. They will have been cranked out of a factory with very little concern for quality or perhaps even safety.

Save your money and buy a REAL tube amp from Will Vincent (autospec). I have his SE45 amp and it is superb! Need more power? Will can build you a 2A3 or a 6L6/EL34/6550 single-end amp! Beyond these PP is needed for more power: his Dynaco ST70 clones are excellent! 

Read the current thread, First Tube Amp. The OP is auditioning a Yaquin, a highly regarded Chinese built tube amp found on Amazon.
  These seem to be a cut above the mass produced Chinese amps and may be a keeper.

Also, sensitivity of the speaker is not an indication of how well a low power amp will perform. You need to look at the impedance at any given frequency.

YOU need to read the current thread. You are confusing this OP with another. This OP has not purchased any tube amp as of yet, ( including a Yaquin ), just sayin. Best.....

@roberjerman, "Save your money and buy a REAL tube amp from Will Vincent (autospec)"

I think that's a more than excellent way to go.  Will's standard rebuilds are Dynaco ST70 restorations with upgraded parts and aesthetics.  Considering how many of these amps made 40 - 60+ years ago still work well, you can't go wrong.  With modern resistors and capacitors, what too many consider as the lowly ST70 can hang with almost any modern amp, and beat a lot of them.  And as also mentioned, if you want a different flavor or spin on thing, Will does a lot of custom work