Now that you have decided taking your wife along is the best idea, here are a few things to look for as well. Ask about floor models. Alot of machines are being replaced with new models, and you can sometimes get a higher priced machine for much less if you buy a floor model. It should come with the same warranty, and lessons. Additionally the majority of shops will have sewing machines that have been used as trade ins, and honestly some of these are very nice finds as well. I don't think you will get a warranty, but you should be able to get lessons. The same here, you could be getting a higher priced machine for much lower.
One of the main things you do want is for your wife to sit and try it out. Do not let the sales clerk do all the sewing on the machine. Its good for them to show you the features but the person that is going to use it should be testing it. Kinda like buying a car, you test drive them. Same idea here.
And who ever it was, that suggested the card, with the gift certificate inside, now thats an awesome idea!!! Love it. You may also find some great sales after Christmas. Same applies to sewing machines as everything else. Good luck and be sure to keep us posted.
As for likes, I love my Babylock!!! Quest Plus. But even though its been discontinued, its a bit above your price range. Unless they happen to have a trade in sitting somewhere : ) you might be able to get it for the price you have in mind.