There are an overwhelming # of homes in the $1,000,000+ range in the Lower Merion area however million dollar homes are selling. I think the best advice I could give you would be to get a complete analysis of market statistics and adjust their price accordingly. While their sale may 'adjust' the neighborhood comparables, an agent's primary concern is to represent their client's needs first and foremost. If your parents need to sell, that should be the paramount concern. With proximity to Center City and Blue Ribbon School Districts, the area will not suffer long term and will continue to adjust according to the market. Please feel free to contact me if you have any further questions or concerns. Thanks!