I have thus far noted that in general cartoonists charge no less than £50 for a single cartoon, some may do it for £20 a cartoon, but that is the base rate. It is usual to pay in the hundreds not the tens for a single cartoon depending upon its usage.
'Usage' is a key factor. The more people that will see the cartoon and the greater exposure it reaps for the publisher etc. the higher you're likely to be asked to pay for the cartoon.
For example:
You may pay as little as £20 for a caricature that is drawn for a personal gift but you may pay £200 plus for the same image if it is to be used for promotional, advertising features etc.
Meanwhile another factor affecting price is skill. Skill these days may reflect more regarding technical skill than artistic. Though artistic skill is of course and always will be the most important factor, that skill has be translated onto printed and online products if it is to be used for commercial purposes.
A lot of time and skill is required in the modern age to create cartoons that can be used for printed and online purposes. The path to learning can be self-taught or via a variety of courses, but it is a steep learning curve which takes a lot of time, patience and tolerance, especially for the artist who isn't keen on technology.
There are artists who can draw brilliantly for example but who do not have the technical skills to put their image online, edit it digitally or prepare it for printing. The more technical and artistic skills an artist has, the more they are likely to charge for their work. These artists fall into the realm of graphic designers due to their graphic design skills and may even be degree qualified or trained in order to offer these enhanced image editing results.
This is no different to any other skilled trades person who charges more based on their training and individual skills.
Regarding how much time it takes to complete a single cartoon. It is closer to hours and not minutes. Thus if you are recruiting an artist for a paid post and want to pay an artist their 'working' rate. Consider:
How much artistic and technical skill is required for the project you have in mind.
How many images are required, then consider each image is perhaps a days work - this will help you with a fair rate per image.
How the images will be used. Is it a non-profit project or are there profits involved. How many people will see the art work?
Regarding those seeking FREE artist services:
There are always people who will work for free (initially) but they don't work free for just 'anybody' for free . There has to be substantial evidence that the project will be 'worth' something to the artist either via good and demonstrative exposure, building up a useful portfolio, or guaranteed future profits.
If you are writer seeking an artist to work for free you thus need to first demonstrate YOU are a good writer who has the potential and the contacts and perhaps a promise to get published with profits.
Finally, art is a passion but for those who do it for a living it has to pay the bills so when working artists are asked to donate their considerable time and skills freely, while it might be a nice idea in a perfect world...it doesn't put food on the table.
I hope this helps folks!
EDIT:
Someone mentioned (in another thread) pay rates for comic art varies.
Pay rates for comic strips vary but not greatly.
Poot comic for example pays around £100 for a single page (about 5 cartoons). This rate is recognised as 'low' and bottom end pay scale. But many artists feel it's worth it because the comic receives massive publicity both in printed and online form.
So if you're offered $1 a cartoon, clearly that's not what you'd call a 'paid' gig.
Syndicated comic strip cartoonists get paid 'a LOT' more for short panel strips...they can earn in the hundreds of thousands...but that is the TOP end of the scale. Kind of like being the Mariah Carey of cartooning!
In essence this post has one purpose, to help other artists gain the recognition and appreciation they deserve.
If as an artist you are struggling to make your art pay...confidence goes a long way along with balls of steel. I have a cartoonist forum http://www.cartoonist-forum.com if you want help with publicity, peer review and support from fellow artists who are at a variety of levels but share the same passion as you do for art pop along.