The Frankensteining of Amplifiers

There is more than one way to great sound. Buying and selling is not for me anymore. Far too much hassle and cost. Those of us with solid DIY skills and experience know how greatly we can improve upon a nice sounding piece of gear.  We know because we have been there and done that with mods and upgrades.....over and over. We know. Astounding the sonic gain that can be realized with our stock gear. Astounding. Well, not all know this because they have not done it and learned over the years. Just be open minded and understand there are many roads to audio enjoyment. 

As a modded for over 20 years and a Previous Audio store owner 
I can tell you this most electronics have average parts at best ,
unless spending well over $10 k , why because 25% or less actually go into the product including the case ,the rest is overhead ,and dealer markup. Why do you think Dan Modwright 
has been so successful in the past .Loudspeakers even more so. 
I upgrade every piece of equipment in some fashion ,digital you are very limited ,unless it has output coupling capacitors , 
amplifiers for sure plenty of resistors , capacitors, wiring 
and most equipment have Cheap gold over brass connectors 
which truly hurt your musical fidelity ,for Copper has 4 times the 
conductivity and Much better sounding ,my whole system has 
gold over High purity Copper as well as all my wiring is the best Solid Core Litz !6-9s OCC Copper porous Teflon dielectric .
VH Audio Best .by having just the same ultra purity wiring 
throughout your system it creates great system synergy,high purity Copper connectors just add to this .Everything in the audio chain count including quality Fuses and power cords. 
If you send me an email  or state a list of the brand parts type 
of upgraded parts I can tell you how good a job they did .

I just read the upgrades , I know Chris Johnsons work well from Parts Connecxion and the list of parts is very respectable , noticeably better then stock. it would have been nice to see inside but that is pretty respectable 
and you do have a warranty . I would say go for it .