Hi rl,
I've put out, and had delivered a lot of leaflets, about 10,000 over the years I reckon, and the results are pretty disapointing. I'd say you'd be lucky to get a 1% success rate with them.
I reckon you're going to spend about £600 on those 30,000 leaflets (my last box of 5000 cost about £100; A5 size) and to get them delivered would cost about £100/£150 per 5000 leaflets, so another £600 to £900 quid.
If you think you're going to deliver them yourself, its not easy work delivering leaflets.
And 30,000 of them is just about every house in Lancashire; I think Chepstow has about 5000 houses; though it is small town.
I reckon you're better off buying some work and starting from there; or go door knocking.