A friend of mine was raving not an hour ago about the tea at the Boston Public Library. The tea is served in a room that looks out on the court yard, and she described a three-tiered plate with scones and all the accompaniments, several elegant tea sandwiches, and some pretty pastries. The cost was $22.
I just went to L'Espalier and the review is here: http://chowhound.chow.com/topics/848995. The price point of L'Espalier can be found at their website. Compared to the Taj, Four Seasons or Ritz-Carlton, the price point is not too different. The food is really wonderful (still dreaming about their cheese course!) and the atmosphere is modern, but intimate. Service was professional and prompt, but not overbearing. All in all, my experience there has been absolutely fantastic! In addition, they have one of the very few tea sommeliers in the country, Cynthia Gold, of whom I am a BIG fan. You will not see oversteeped tea at L'Espalier!
The other place I enjoy is Upstairs on the Square. Quirky with an interesting atmosphere. We went with the chow pups for their Holiday Tea which was very reasonably priced and a shade cheaper than the Taj, etc. Go to their website on pricing and menu for their regular Afternoon Tea. For my experience, the tea was quite nice, but a touch below L'Espalier. Service was good (not great) and the food was filling and delicious. For the price point, it was a wonderful value. More importantly, they had a really appropriate tea service for kids. Not dumbed down, yet playful to get the kids interested.
Please let me what you choose. I am always on the hunt for a good place to have tea!