I am targeting small local businesses and franchised venues.

I've avoided big chains that are centrally owned, since I can't talk to an owner.

Is it still worth contacting them? That is, is it likely they have a budget (advertising?) allocated that they can spend from?

Why wouldn't a BIG chain franchise have an advertising budget?

Go for it

Most of the Big Box stores' advertising is handled at HQ
We have sold to big chains...ie: homedepot, sears etc... BUt it really is IMO a waste of time. Some Corps will allocate X (small amount) for managers to do local marketing but not many. It depends on the Company.... Game of Numbers, hammer the mom and pops forget about the big tops. They will lead on on a wild goose chase that will waste $$.