I guess it depends on the style of your home and your desire for perfection vs finances. I do think that in some older homes the private areas were less fancy. If you think you will regret not getting the expensive doors perhaps you should at least for the 3. You might get more responses if you posted a pic of the originals and the 2 choices.
Good luck.
Kathy

It was extremely common for the doors to be different upstairs and down ... as you go from guest to family to servant's areas the materials get simpler and cheaper.

What style and era is your house? If there are similar houses in the area, I'd try to find antique ones before spending $1000+ (with shipping and tax) per door. Check out local architectural salvage stores, Craigslist, and even eBay (you can restrict your search to local sellers). Avoid painted doors if you can because they're expensive to strip (and tedious and messy to DIY), the paint may contain lead, and you won't be able judge the condition of the door very well. Also, pay attention to whether the doors open from the left or right.

Be sure to bring pictures and measurements (width, height AND thickness, as well as the sizes of the panels and the width of the stiles and rails) when you go to look at doors, especially if you're trying for an exact match. There are lots of subtle differences between doors that you might not notice if you don't have good pictures for reference. For example, I'd like to replace a few of the 4-panel (2 over 2) doors in my 1870's house, but so far, I haven't found any with similar proportions (long upper panels and short lower panels) and panels. (My panels are raised, but only slightly.) I was amazed at the variety of 4-panel doors out there. (I decided to stop looking for now until I finish some other projects.)

On Craigslist, search under Materials. Lots of contractors sell materials that they remove from remodel jobs, usually more cheaply than you could find them at salvage stores. You can also post a free wanted ad, but be sure to have great photos and be very specific about what you're looking for.

No reason to match upstairs and downstairs. Painted up and stained down would be fine, and perhaps not unusual. All of our trim downstairs is clear finished cherry (most def not stained!) and upstairs is painted. I'm not sure anyone ever notices.

In our old house, (1884 farmhouse), we had all the doors matching upstairs and down. I've moved 2 of the original doors (4 panel stained) on the main floor to other locations that were missing doors or we added one, and replaced them with 15 light doors to improve visibility and to match the pairs of 10 light pocket doors we added. On the 2nd floor, all the doors were original 4 panels and painted- on the 1st floor, the 4 panels are on the closet, the bathroom door, and the basement door, and there are also 2 pair of 10 light pocket doors, and 2 single 15 light hinged doors, and there will be 1 swinging kitchen door that is a different style. The basement level originally had no interior doors since it was unfinished - we've added simple pine 2 panel doors from a salvage yard, so they look old, but different.

Always ;-)
Hunzi