Good luck finding a "brand new one in an unopened box"......they haven't been made for years. Unless someone bought one from K&M years ago and stashed it under their bed. They are great amps; I have Ltd. #11. Only about 25 of them were made, if memory serves me correctly.
One went for $3,995 on ebay:
I am pretty sure that there is a place in NYC that I have heard had a small stash of K&M amps that never sold. They have had them NIB ever since and have not lowered their price. There was an Opal for sale not long ago that was essentially brand new fully equipped with NOS 7581 tubes and all. The used one isn't worth the asking price IMHO and is probably worth somewhere around the $2500-$3K tops but the new one is probably worth more.
You will never recoup your initial investment on a boutique amp like a Two Rock. As a case study-
I bought that Opal you speak of- sat in the office of a Boutique amp dealer for 10 years, and then was put on sale this year. It's already seen 2 owners before I bought it, both had it for less than 3 months. It was a good investment for both of them tone wise, not financially. Same with me, though I don't plan on selling it.
First owner paid around $4k because it was New Old Stock from the NYC dealer- I waited 6-7 months and bought it used for a $1400 discount. I don't think it's worth the premium. I waited because I knew what was reasonable for me, and sure enough, it came around eventually. Your friend will never recoup his expenditures on a new Two Rock. Unless it's very very rare, like 1 in existence rare, or it has some history like it was signed by xyz artists and dumble coughed on it and so on, or a mayer sig, it won't happen. That LTD is nice, but for what you gain over similar K&M/Two Rocks is marginal for that kind of extra dough. Just my thoughts.
There will always be folks who prefer to buy their stuff new and those who don't. I personally think that if you can get the deal you got that us the best route, but you have to be patient. I just had a similar experience buying a TS1. It sat in a shop for two years before I bought it, and I was able to snatch it up for a price I could afford although it was still more than I ever thought I would pay for an amp.
Its worth it too me. The TS1 may not be Two Rocks best amp although I like what it can do. I do wish it was 100w though.
In my eyes the TS1 is one of their best!! Enjoy it. But yea, buy it because you want it. Not because it might sell for more, some umpteen years from now.