Just seen a casting offering a 20 percent discount if the booking is confirmed and paid in advance. Is this a good idea with the aim of eliminating the time wasters and flakey photographers or would you choose not to pay for a model in advance even if she had great references?
No. I don't pay anyone until I'm confident that never having contact with them again won't cause me any problems. Bitten too many times with forgotten ID, etc, which, although promises of, "I'll send it first thing in the morning" were made, it never turns up. Once they have the money they lose interest in any follow-up needs.
£20/hr, shoot at models home up to nude. Seems like a good deal to me.
If you booked a studio for 4 hrs, it might cost you £100 in studio fees and if the model no-showed you would be liable for the costs as well as the aggravation of wasted time. There is an element of risk in booking many shoots. You can minimise this by working with experienced people with lots of good feedback and shooting at your home or the model's home.
In this case, the probability of losing your money is quite small. I expect you would also get a good discount if you paid a deposit of £20. I think this model has experienced a lot of time waster photographers, so this is just her way of weeding them out. Maybe other models tend to be booked by more reliable photographers.