Though i can't speak for ebay or directly from the producers website, i had a very pleasant experience with aliexpress. My 29er frame cost me stupidly low 220€ from Thrust. QR, though the dropouts can be changed to work with thru axles, which are sent together with the frame. You also get a starnut for the headset, the headset bearings, seat clamp and other bits and bops.
Paid via Sofort(which is working via the bank account and very safe. Is very popular with German and Austrian online bikeshops because they get their money very fast)
Took about 1.5 months to arrive, though i had to pay 20% import taxes in Austria and the general fee of at least 10€ which was 72€ in total, so the frame cost went up to just under 300€. Still ridicilously cheap. You can opt for some "special"kind of shipment which costs about 50€ or sth and that should help to clear the border without paying any taxes. This would only be effective if the frame costs more than 300€.
Or you can also tell the seller to declare the frame to have a lower value than the actual one. Might work, but not always since the guys at the border know how much a chinese frame costs by now