Never heard of the vendor so no one can say whether the merchandise is best described as crap or otherwise. Given that it is a summer suit, mocs. are as formal as you need be. All the others are far too heavy for summer.
There is every chance that such a thing will be faked. In simple terms if something can be "faked" someone, somewhere will do so.
When buying on an online auction site extreme caution much be exercised and items are best avoided. On eBay even the most honest sounding trader may well be selling fake goods; the benefits of selling in one in five items as fakes is huge, most buyers will not even know.
Ask yourself why are things cheap on eBay? If the manufacturer had...
Correct, I have not owned a sweater for many years now, don't need them. Sweat does shirts no harm whatever, all mine are made by Ascot Chiang in Hong Kong and none over a twenty year period has suffered any harm.
"Finance" is a very broad church and does not help over much but there is nothing inherently wrong with it for business use.
What is of greater concern is who "E Thomas" the cloth supplier actually is and whether "Super 150" is robust enough. However if it one of half a dozen in use it should not come to much harm. Expensive for what it is and from it you have bought it.