Tuba Exchange's house branded horns are made in China.
Haven't tried the TE tubas, but have tried the euphs: they're decent players, so
assuming the quality of materials and workmanship are up to snuff, they're probably not bad for the money. Double-check and verify specs to make sure everything's as advertised, though: the shank on the TE euph, for example, is smaller than the standard large shank, but larger than the euro shank. My large shank Schilke 52E2 and their demo Miraphone BT-17 stick out about 1/4" farther on TE euphs than they does on my Sterling Virtuoso or Besson New Standard, the TE mpc bottoms out against the end of the leadpipe on both of my horns before the sides of the shank contacts the receiver, and their demo BB1 bottoms out in the TE euphs.
A few things to bear in mind when considering a vendor-branded horn:
• the warranty's only good if the vendor's around to provide service: if the vendor goes belly up, you're hosed;
• for the forseeable future, at least, you're likely to only be able to get spare or replacement parts from the vendor;
• you'll likely have to take/ship the horn to the vendor for warranty service: if you don't live close by, that can be a costly proposition, esp. if you have to pay shipping both ways;
• if you're not local to the vendor, make sure your local go-to repair tech/shop will work on Chinese-made horns: although the quality of Chinese-made horns is improving, the poor quality and shoddy workmanship of early Chinese-made horns led many shops to refuse to work on them.