Basically 99.9% of people who call you with a fantastic advertising opportunity are selling you a white elephant.
In your position as a new starter it needs to be the other way around, you work out how you want to spend your money and stick to your guns. Only do proven things. You could literally pee thousands up the wall each year if you went with all these ideas put to you by someone ringing you up out of the blue.
As and when you find yourself a few hundred here and there that you don't mind taking a punt with, by all means explore some other avenues. Probably a few little gems out there waiting to be discovered. But every penny counts in your first few years and losing several hundred pounds on a failed advertising campaign could be a disaster.
The online directories tend to massage the figures a little bit, like they'll tell you there were 2,500 searches for a carpet cleaner in your local area last month or some rubbish like that. I offer them all the same deal. Give me 3 months free trial and if it works I'll start paying. They rarely play ball, my argument is if they're so confident this will work for me isn't it a no-brainer for them?
If you do play this game DO NOT give any bank/card details at this point, they don't need them despite the lies they tell to get your payment details. You'll find they will start taking payments despite you cancelling, and getting money back off them is a nightmare. I think a regular on this forum got scammed in that way some time ago, can't remember who it was or which company was involved.
I've got more work off a free yell.com listing than the paid for one I used to have, work that out!