Neighborhoods near Perrin Park (Hardy School) and Pilgrim Road (Bates School) (both off Weston Rd. but in different directions) are popular and have homes in that price range. The Farms area (Schofiled School) is also popular and homes do come on the market in that price range.
What you will need to focus on in addition to the popularity are the characteristics of the neighborhood that make it popular (Is it walkability to town/train or is is proximity to a school or park?, for example). What is appealing to some may not be high on your list.
Also, you should consider what style home you are most interested in purchasing. Wellesley is a place where most houses are (and many homebuyers seem to prefer) traditional colonials. So if you have some flexibility in the style of the home you buy, you may have more choices, particularly in this price range which often captures ranches and split level homes.
A quick search of the current inventory shows about 17 houses on the market between $650K and $850K (a bit below and above your figures, just to capture inventory). Maybe one of these will work for you. Otherwise, there is often an up-tick in inventory now that the summer is over. Keep an eye on new listings.
Best of luck - Andrea