The SMT660 is about 510kg (1,120 lbs) gross weight; approx. 40 feeders can be packed in the same crate which will increase that slightly. I know you've said you've already arranged the shipping now, but I always ask for FOB terms and arrange my own freight forwarder as it will normally be quite a bit cheaper than having the supplier arrange the shipping, and it is door-to-door. (Note that the shipper cannot guarantee the duty/taxes that are applied, only advise, so there is always a chance you'll get hit with further fees once it hits home soil. That's another reason to use a forwarder in your own country.)
For reference I recently imported 2x SMT660 into the UK for £560 fully insured against loss or damage. The commodity code to use for import is 8479897000. Importing that commodity into the EU is tariff-free (and as others confirmed in the replies above it should be the same for China->US as well).
Bringing into the EU I had to pay 20% VAT (a paper cost as I claim it straight back again, but still ties up the cash for a few weeks). I don't know what taxes you would pay in the US.
Does the $2,000 USD shipping cost you quote include your VAT-equivalent?
$11,900 is the standard price for the ball screw version ($12,900 less the $1,000 discount they always find for you), and I got 20pcs 8x4 feeders included in that price. The trade assurance on Alibaba is now extended until after you receive and inspect the goods as standard, which is handy.
I've only set up one machine so far and done basic testing, but so far it seems fairly typical of Chinese equipment in that price range - well put together mechanically, reliable brand electronics, but a bespoke controller board and let down on the human-machine interface. (You will get the newer software with yours that supports the 8 head model, which is slightly less confusing to figure out.) The ball screw variant is so far rock-solid during the highest speed movement (using the patented 'glass of water on top of the chassis' test, aka the 'dinosaur detector' test). Replace the monitor with a 19" EPOS touch screen and it is quite usable (1280x1024 resolution - their software does not scale to anything else). You will need to re-tension the transport belts, but apart from that you can test right out of the box.
Note that YX don't make these machines (they may assemble them, but they are not their design - they are the HW-T6SG-64F) so parts are available from a few other suppliers. Interestingly the source manufacturer is a bit more expensive though, and YX always seem to have <3h response times even when China is sleeping.
Photo is immediately after delivery so that is what you get out of the box (feeders are extra).