We all get emails from places we've bought from and I had two today that were both offering a MBP, 15", for pretty good prices. The devil, of course, was in the details. While OWC and B&H are both great, reliable companies, you still need to compare deals closely.
These were both mid-2017 models, factory sealed. But only one could still be covered by AppleCare. Both had the "Touch Bar" but one had an earlier model graphics card. Both had 16GB ram, but one had a 512SSD while the other was 256. One had "No State Taxes" (if applicable). One had Parallels Desktop for Mac installed.
Even though Apple hardware usually has fewer options/configurations than some PC's, there can still be details under the aluminum that cause price differences. Know what you need before standing in the virtual line.
Beware of temptations of "$100 less for the first 50 orders"! But keep a lookout form them if they apply to what you need!
Suggestion: Every time you pass up a deal, try adding $50 or $100 to your purchasing fund.