I like the packages, and think the price point is pretty darn good. I do think that you should be accomodating, and take the cost of a DJ out of the Silver package IF they really want to bring in their own DJ. Make that number low so it doesn't make a whole lot of sense to bring in their own, but don't force it on them. ...Maybe take a $300 or $350 deduction out of the package if they bring in their own DJ. Sure they could be briging in their cousin, or a friend, but if they are paying someone...whoever they get for less than that is not going to be much monetary benefit to do so.
Also, starting out, especially the first year. You WILL get people coming in who ONLY want to rent the space, and tables/chairs. They won't want ANY of the rest of the stuff in the Silver Package, and want to bring in the catering, and everything else themselves.
Will you deal with these people, and custom quote them? OR will you choose to tell them "Sorry, this is an all inclusive venue, and the Diamond package is the lowest we offer" ....I doubt those customers will drop $6500 for the venue and tables/chairs, LOL.