First thing I'd look for is a tack consignment store in your area! It's a good source for blankets, bridles & martingales. You can get more for your $ and see what the leather looks like after it's been used for a while. Just make sure you go for well cared for pieces and check stitching, etc. carefully.
For new saddles, Intrepid is worth looking at.
In terms of priorities for shopping, start with what your horse will need to be comfortable. Blankets? Boots or polo wraps for riding? After that, think about your grooming & tacking routine. Is there anything the barn doesn't have that you need or that always seems to walk away so you can't find it in a hurry? Prioritize those things so you can enjoy your time at the barn and not be stressed about finding missing pieces in time for a lesson.
Finally, think about what you absolutely need (i.e. some sort of storage container) vs. what you'd love & be excited to have (a nice trunk). Economize or do without a few of those now and let your husband provide a few of these "special" things for birthday/anniversary gifts. Most likely, he'll be happy to have gift ideas (not that all men don't adore shopping ;) and can be the hero when he gets something you're really excited about.