Value on a brick vs. vinyl sided home?

[Erica Nagle]

Hello, I currently have two investment properties in the Detroit area that I'm looking to sell. I got an offer from someone who later backed out saying he thought the whole house was brick but when he drove by saw that only the front was brick and sides were Vinyl. This seemed odd to me that the type of exterior would have such a huge impact on the value of a home that is less than 1000 square feet. If it needed new siding then okay but it's all in good condition. Is this common in the Detroit area to heavily factor in if the building is brick or sided in Vinyl? If yes, why? I currently live in Boston and grew up in Iowa and neither places is this such a factor.