Graco is who I would go to if I had a problem with their product whether or not the store I purchased at was in business.
In fact, I have done so on more than one occasion and they have a wonderful customer service team. I have no complaints from any of the times I had to contact them, they tend to go above and beyond.
A friend also had to contact them when she removed a harness from, I think it was a comfort sport, but for sure a seat that it was not supposed to be removed from, and they absolutely went above and beyond when she called for help in getting it back in when she couldn't figure out how. After letting her know she should not have removed it and would not be able to put it back, they sent her out a new seat. They absolutely didn't have to do that.
I've called with problems with a couple seats as well as a pack n play, and they were great every single time.
I would absolutely buy the seat you are interested in without hesitation, especially if you can get a great deal on it with the trade in.