Speculative work - how much?

[PRfreelanceWDYD]

Are there any PR freelancers who could give me a steer on how much work is reasonable prior to being appointed? I've been talking to an agency who is pitching for a piece of business and so far I've offered an outline strategy, contacted a publication to start brokering a commercial deal and offered a couple of opinions. All without charge on the basis that if the business is won, they'll fling a bit my way - but not much. How do I phrase 'Enough is enough" whilst maintaining good relations and showing willing? TIA for any guidance - because this industry is relationship based, boundaries very easily get blurred.

My freelance work is in a different area to yours so not sure how relevant my answer would be, but in siuations like this I refer to 'my policy' (which exists only in my head) and suggest a reasonable price for what they are asking (which might be a good price if I really want the job).
So you could say, 'my pre-contract package includes xxxx, which I have now completed for you. I would be happy to help with xxx for a reasonable fee'.
For me it seems to happen more after the job has finished, they'll come back with 'can you just add this' type requests, so I've learnt to be vey clear about boundaries from the outset.

Thank you perfectly, that's very helpful. It takes the personal element out and wrapping it in a 'policy' makes it an easier message to deliver. I've now added a finish date to the costings to ensure I don't get the 'Could you just..'.

Yes, it definitely helps to take the personal element out of it. When I first started I was terrible at this side of, I've become more hard hearted as I've gone on!