I am happy with ManyPixels
I use ManyPixels to order custom illustrations for content marketing purposes on my website Salarship. The illustration format is .svg and I use them as a header for articles and other content formats. I pay $800 per month and the output is about 35 unique illustrations per month, which is relatively cheap compared to the most expensive competitors. The quality of the illustrations is most of the time really good. Sometimes if it is not up to standards or if there is a miscommunication problem, I ask for a revision and the revision is always of great quality. Before using this service, you must be aware that some elements in the illustrations can be reused in different illustrations. This is not a problem for my particular case usage, but you should be aware of this. Overall, ManyPixels is a great service. I have used it for 8 months and it is perfect for my content marketing needs.