Forex sales tend to be a convoluted mess. Some people love it, while others hate it. Because I fall into the latter, I'll skip commenting on the domain in your title.
SilentVacuum.com is actually a relatively good name. Even though "Quiet Vacuum" is the word combination that leads for search results. the word silent is used in different vacuum cleaner models. On eCommerce sites, there appears to be sufficient traffic searching for silent vacuum cleaners.
Appraisal: SilentVacuum.com can fetch around the mid XXX range ($400-$600) in its upper limits.
A targeted buyer may pay higher while there are others who may buy lower.