Lowest single unit sample price in China is actually about 440.00 FOB - which means you pay shipping, if by sea it's a few weeks (ie: 1-2 months) before you receive it.. a single unit price will also be charged, about 100.00 more than the same price if you take 50-100 units or a few pallets to a container full... then you will see 400 maybe even 350 a unit but that's an investment without shipping of 35-40K USD and you must pay 30% upfront and 70% upon order completion with lead times (in addition to shipping times slow method) of 21 to 90 days because the vendors order them in many cases from Bafang Directly, as I said
In your case you would be ordering a Sample so the price would not be the bulk price (though a reputable dealer will deduct the cost paid for the sample if you place a bulk order later, it's something).
If you want the world and you want it now!? You going to pay for Express Shipping which has grown exceedingly expensive from China of late even via EMS, last quote I had for a sample BBS02 kit was 142.00 Door to Door in 5 business days + 2 lead time for my changes to be incorporated.
End result:
I paid 520 FOB for single sample (got lucky) add the 142 for shipping and total cost was $662.00 Delivered.
With that as a Sample its basically As is and while it should be their best work in the hopes you will order more, then you will pay for a fixed sample and so on and so forth till the sample meets your needs.
One further issue, when you deal with a reputable US vendor - they either have in stock, offer a discount for pre-orders while they come... but in nearly every case they offer support and the factory bafang warranty. This is because they do bulk work with the vendors (I don't know a single vendor who deals directly with Bafang to be perfectly honest, not when it comes to ordering it's all done through vendors). If you order from China, you get the hidden costs and pay a small amount less (about 125.00) but have to suffer all the difficulties to obtain a sample unit which isn't really simple if you've never done it before and it's 12 hours offset to US timezones, so their mid day is our mid night... add the second language english and communication is difficult to say the least. If the vendor even allows you to return the item for a new sample (not likely they usually just say they will take it off your bulk order, you have no intent on making so it's a lose situation for you solo) you still have shipping costs in both directions and if expedited thats almost 300.00 to a from China.
With a US Vendor shipping is reasonable and I don't know a single Reputable online vendor (not all are, ask around first or go with a from a known Member purchase) who would even make you pay return shipping, they would email you a PDF return label to ship it back and send you a new one immediately. Their goal is satisfied customers, the whole process even using ground is 4-6 days
That's my .02 c I hope it helps you understand the pricing over the map.
-Mike
PS: No I don't have any BBS02-750 currently, sorry or I may offer you the ES special which comes to 12% over my net cost
What you wind up doing is your business and I'm not attempting to