I rendered the GPU modified v1 scene on a Paperspace P5000 machine running Blender 2.81a, which took 1h45m53s (manually timed, from 21:23:00 to 23:08:53). At $0.78 per hour this comes down to $1.35 total cost.
You basically get a remote desktop connection to a virtual PC running Windows 10 in their data center. For GPU rendering you would generally want one of their GPU instances, which are priced as follows:
P4000 $0.51/hr
P5000 $0.78/hr
P6000 $1.10/hr - this one should be about 30-40% faster than the benchmarked P5000 for GPU rendering
In addition to that you always pay a minimum of $5/month (50Gb) for storage per machine.
Compared to a renderfarm, you get a lot more control over your render, you can run any blender version/plugins you want, you can also use it for modelling if you have a weak computer and rendering starts instantly the moment you start it.
They are planning to add RTX GPU’s, but there is no ETA yet. If you render a lot, Shadow is also worth considering, where starting from April you can get a machine with an RTX GPU for a fixed monthly price. For blazing fast performance Xesktop also looks interesting with 10x GTX 1080Ti per machine at $6/hr.