spreadmanagement.com is available to register
There are also many reg fee alternatives that someone could make up that are equally as good as your domain so it's hard to see why they would choose to pay you a premium.
It's really not possible to appraise 'brandable' domains because there are millions registered and you have to hope for a lottery-win sale - nobody can say who *might* want to buy it when it's not a strong domain.
Personally if I saw it as available I'd leave it.