A domain value mainly depends on the age of the domain (how old is it), its exact Google searches that it gets per month (what can be an indicator of its traffic), its keywords (are they strong and do they make sense), its brandability (is it short and easy to remember), whether or not it's a COM domain (domains in the COM extension have the most value), etc...
Of course for one person your domain can be worth $10 and for someone else thousands. So it also depends on what someone is willing to pay for it. A company can "usually" pay more money than an individual.
Glucid.com sounds like a nice brandable domain. If it were my domain I would probably try to sell it to this company anywhere between $500 and $1000 USD (unless it's a fortune 500 company and in that case my price would be tenfold ;) ). But like I said : Value is in the eye of the beholder.
Asking for an offer is always good, you can always counter the offer if you don't like it.