Reg. fee's+/- each/any/both, IMHO.
With the "ZERO", making these 3-character domains ... not a lot of upside, as there are many many of these types in the daily drops. Letters are better than, say, X's,Y's,Q's,Z's, however.
Good Luck with your sale(s).
Don't be fooled by the fact that it's 3 characters. Chances are unless the name is an actual word (pie.com) or catchy (abc.com) or is the abbreviation of a company or organization (ibm.com)...It's gonna be worth Reg.fees.