VPS L from Contabo should be more than enough for up to 150 accs. Just take into account that you have to pay monthly licence fee for windows additionally. Hetzner also has VPS and they do allow you to install with your windows licence key (cheap on eBay and worked for most here). However I have no experience with Hetzner VPS. Dedicated server might be of interest once you scale up.
Well… but @fine also inquired for 100 acc to run. That is a different story.
I am not saying that your proposal is not good. It is just that the long time members in this forum recommend other providers. Anyhow the world is changing and maybe the super cheap approach is working one day.
I had up to 350 accs on VPS L. That was a very big pain. Had to use night mode so that not all accs are running at the same time. 500 accs smells more like you need a dedicated server. I recently started using a Hetzner EX42. Currently have 180 accs on them and it is running smooth. Will scale up but frankly speaking do not know what it will do with 500 accs. However there are plenty of threads in the forum about server for 500 accs.
Advantage of Hetzner is that you can install your own windows licence. And long time members seem to agree that a dedicated server performs better.
Thanks for your answer @Larsometer. I might try the XL just to test its limits. But if you said that the L barely managed 350 accounts then 500 on XL should be the same. Who knows. I will test it and come back with some updates
I used Contabo for a couple of months.
First it was great. But, when tried more accounts [180+] contabo wasn’t enough.
May be I haven’t configured Jarvee correctly to make use to the VPS.
Anyway, I couldn’t wait and started using Hetzner. [Thanks to all the pro users like @dimitri@dma0245 I got to know about Hetzner]
Purchased a Dedicated server from their Server auction, Installed Windows and so far so good.
If you are planning to scale up [You should scale up though ] Hetzner is the best place.