First of all, I don't know the Babylock machine you are considering.
I have just purchased the Bernina 820.
The question I would have ... are you happy with the Bernina 820? other than the fact it does not have the embroidery function? You might want to consider keeping it, and purchasing an embroidery only machine.
When I was at the dealer getting my 820, I talked with a lady who previously had the 830, but traded it for an 820 (no embroidery) and the 780 (embroidery only). She told me that the waiting for the embroidery took too much time and this way she could continue being productive, as she kept an eye on the embroidery.
ITA with the others ... if your dealer is not wanting to give you a firm trade value, then keep control of your machine and sell it yourself.
Another thing to consider ... there are more dealers out there! If he's being a bit fishy now ... what does the future hold, if you have an issue with your new machine?