Yes, I know of MCS (hello Joy, if you are following this!) and indeed bought my DS1102E 'scope through them in the early days. But I did pay a bit of a premium. Example: Rigol DG1022 SigGen - August price quote was GBP £325 + 20% VAT, delivered. Current "best" Ebay price GBP £266 delivered, but there is the RISK that customs will take an interest to the tune of a further 20%, of course.
The DG4000 series is still pretty new, so maybe prices are all over the place. The DG1022, on the other hand, is now widely available. And yet, on BOTH occasions, when I asked an ALiExpress reseller to confirm what looked to be very aggressive initial pricing, suddenly the price had gone up! (even though the original offer was still "up" on their site). OK, I get the picture.
I can easily see, B.A.W, how I might place an order for USD $300, only to find my credit card debited to the tune of $450 ("Solly sir this is new plice), and me without a proverbial leg to stand on!
Like my mother always said, "If something looks too good to be true, put it down and come and finish your dinner, or it goes in the dog." At least, I think that was it.