Retainers - how much?

Hi, I'd like to guage some opinion on how much to charge for a retainer in this situation;

Couple first contacted me in March, I registered as CM in April, Baby born 4 days ago and they want to sign contracts next week to guarentee full time place for end of October. I really really need to start making money asap, so feel that retainer needs to be decent percentage of what I could earn if space was filled with a child. I had planned for my retainer to be 90% of my usual fee, imagining this would be for a couple of weeks rather than 16!

They are both Drs, want the place full time, and I don't think money is much of a problem. What do you think? Do I go for 90% and be prepared to negotiate down? Set a flat monthly / weekly fee somewhere below that? I don't think I can go as low as 50% as I really really need to get some money in, and can't guarentee I would get short term contracts to fill space!

What would you do?

All thoughts greatly appreciated! I have contacted local authourity PACEY rep and will ask local CM's at school gate to guage what local people normally do too....

You need to look at it this way too, if you go to high and they turn you down you may have nothing coming in at all until someone else comes along. I always do 50 percent max. Have you only got the one space otherwise you can continue to look for other children too

90% is a bit unreasonable, 50% max I would go with.

Like you, I also had an enquiry for a space in 3 months time when I had just started. They paid me a retainer of 50% of the hourly rate, they actually used me in those 3 months and I charged the other 50% of the fees for those days. :-)

thanks all, after alot more research it seems my 90% was totally unrealisitc, and the national and local standard seems to be 50% so I'm going with that. I still have other spaces I can advertise afterall.

Thanks for the help!