I have un-matching front crowns! Is it better to replace both crowns so I can get a more even size and color? (photo)

Two crowns would look better than 1 because of a perfect match but I would suggest correcting the upper jaw.  Your jaw is very narrow and the front teeth are protrusive.  Your smile says "Look at these two teeth!"  Doing additional teeth could improve the results but if you want to create a beautiful full smile I strongly advist you to look into the DNA Appliance and Epigenetic  Orthopedic/Orthodontics.The results will be better than normal orthodontics, invisalign or ceramic crowns.  Wait on replacing the crowns until you have established a better smile line.Dr Ira L Shapira D,ABDSM, D,AAPM, FICCMOThinkBetterLife.com

I would recommend replacing both crowns at the same time to have the best result. You may want to whiten your teeth prior to fabricating the crowns if you so desire. If you are concerned about the teeth being bulky you should ask your dentist if this is from the teeth themselves or from bulky crowns. 

From your photo it may be a good idea to have both changed so that they are less bulky, less prominent and both match. Your new dentist should be the final judge.

As a consumer, expect to pay well over a thousand and probably closer to two (depends where u live) to get a single front crown to match consistently.  ideal treatment would be invisalign to straighten and then maybe getting the front four done together. If the doc can't show u photos of cases similar he/she did then assume they can't do it. Dobt bother going cheap on this or U could just as easily be worse off. If you find right doc they could redo the one and be fine. 

In this case it would be best to replace both crowns since neither looks perfect. You might also look in to restoring the teeth on either side of the front teeth and maybe some orthodontics like Invisalign as well. The cost varies greatly depending on your geographic location and the experience of the dentist.