Nope they are paying me for my time.
Well you can obviously sell them 'your time' if you like and therefore basically agree to do work made for hire instead.
In which case, you would really need to put everything in writing beforehand:- how many hours do they want you to work them, plus how much will they pay you per hour - as well as: what camera system do they want you to use during those hours that they are paying you for, what lenses do they want you to use, lights, stands, modifiers, computers, software, etc, etc - and then have them sign it all off beforehand OR have them agree to supply it all for you to use, during the time that they are agreeing to pay you for.
Otherwise, you could just turn up with your two hands in your pockets - just like an assistant would do, if you were hiring them to do some work for you.
So in other words, besides billing them for 'your time' here (like an assistant would do), you would normally also bill them for the hire of any & all equipment that they wanted you to use too - and naturally you would mark all of that up +%.
So it would be all about Expenses, Expenses, Expenses
- when it comes to this type of agreement.
Because one day of your time is still just equal to one day of your time, no matter how much they pay you OR whether you use an iPhone or a large format camera system OR whether you use no lights or 50 lights OR whether you take one picture or 1000 pictures OR even whether those pictures are any good or not.
So if you are going to be bill them for this, then it's important for you to understand the difference here, between agreeing to do work made for hire and agreeing to provide them with some images for them to use - because what you would be actually asking them to pay you for (beforehand, when you are quoting), would naturally be very different too.
So rather than saying something like this...
To produce and then provide (X number of) images of (whatever it is) at (wherever it is).
For exclusive use, for (whoever they are) to use these images for:-
Media use: (All Media or for whatever media it is that they have said they need to use your images in).
Period of use: (Unlimited years or for whatever length of time it is that they have said they need to use your images for in the above).
Territory of use: (Worldwide or for wherever in the world it is that they have said they need to use your images in the above).
Licence fee based on the above: $ (the amount you would like them to pay you for agreeing to this).
.. which would then tally with your 'Usage Rights' terms - you would instead list everything that you are possibly going to need, to do whatever it is that they want you do, during the hours that they have agreed to pay you for... and you would then get them to sign for that beforehand - so as to avoid any misunderstandings down the road, as to what it is that they are actually paying you for here.
By the way, agreeing to do WMFH is actually not a bad way to work in my opinion - so long as you fully understand how it works and the difference in how to bill for it - because it usually does mean that you can get to use the best & latest of gear, which you may otherwise not be able to afford.
So it does have it's advantages too - which you can also take advantage of, if you play your cards right