This does vary somewhat - when chicken thighs became a more trendy ingredient a few years ago prices for chicken thighs rose pretty dramatically. I mostly noticed because I was semi-regularly making a very simple slow-cooker chicken chili that used boneless skinless chicken thighs.

Also, where in the US are you paying $10/pound for chicken breast? In the Chicago area even "boutique" organic boneless/skinless chicken breast is seldom above $6/pound, regular full-price conventional chicken breast is typically $3-4 depending on where you shop, and B/S breast is often on sale for at or below $2/pound (rarely below $1.49/pound).