Staybright,
You are too late for this years Yellow Pages as it comes out in a few days time. It has all ways done me well and brings in some good work as well as a few price shoppers. You will pay a lot to go in under a decent sized advert, probably between £300 - £500 depending on the size of advert. They will give you a decent discount on your first year though.
As Paul said you can go in under the federation heading but i don't know what the cost of that is.
I know i keep harping on about it but a well sign written vehicle will bring you in loads of work and its advertising your service 24/7 everywhere you go.
You could also go door knocking, your either good at it or your not ( I'm not ) but if you are that should keep the work coming in.
Are you on a non compete contract with your present firm because you could have problems canvassing the areas he already has ?
Denzle