U need to state ur location.

Assuming u are in Klang Valley, RM10 per light I think is reasonable, or cheap... Read somewhere, forgot where, for new installation (exclude wiring), RM15 per lamp and RM80 per fan, which i suppose the rate is applicable for replacement also.
Somemore if is own condo-man, u can anytime call him come up and settle should there is issue after the replacement. U find outsiders, only 1 or 2 lamps got post-issue dont think they will entertain u.