Renting is probably very inefficient: you can buy a GPU that gives you 10 times more performance for 200 euro:
my GTX 1060 3 GB searches through ~40Mkey/sec.
The 40Mkeys/sec figure is from oclvanitygen. Switching to VanitySearch brings that up to 320MKeys/sec.
Nvidia's 16XX and 20XX series are even better at generating keys. Based off of
DaveF's crowdsourced list, a 1650 searches through 500MKeys/sec using VanitySearch for about 160 euros (and the 1650 Super is probably even better as it has the Turing architecture). That's about the half of the speed of my 1080Ti (900MKeys/sec) at about the fifth of the cost.
It is more of a research / curiosity question than trying to find something specific.
I was looking at the difficulty in generating vanity addresses with specific prefixes.
For example (at ~4Mkeys/s)
5 characters case sensitive - starting with a lower case (15,318,045,009 difficulty) - 50% takes about 40 minutes.
6 characters case sensitive - starting with a lower case (888,446,610,539 difficulty) - 50% takes about 36 hours.
So I was simply speculating as to how many Mkeys/s one could generate for a reasonable price. The VPS I use with 6 cores costs 35 euros/month.
Of course, a GPU will cost more - but how many times more? The cheapest GPU (35 cents/h) here (
https://gpurental.com/) costs $250/month. The most expensive ($1.35/hour) costs $920/month. However, I don't have the experience to know what the specifications of the GPU actually mean.
Here is a cheaper example at $99/month (
https://www.gpuserversrental.com/) using 6 x GTX 1050 2GB.
So they are not hugely expensive though the price ranges far more so than for a CPU-based VPS.
Are you going to have to run at 24/7? On gpurental.com, I see a 7x1080ti rig for $1.35 USD/hour. That's 6.3GKeys/sec. 35 Euro gets you about 28.5 hours, for a total of 646,380 GKeys generated. Your CPU based VPS, assuming best case at 4.5MKeys/sec running for 30 days, gets you 11,664 GKeys generated. At the same price, using the 7x1080Ti rig, you get about 60 times the keys generated.
Note: Generating split key does decrease speeds. I think renting the 7x1080ti rig is much better regardless though. If you can find someone offering the 16XX or 20XX series, it will probably be even better performance/$.