If it's for web hosting, you could use apache with php installed, combined with a MySQL server. Running only that would use about 200-300MB of RAM. So, at real peak, maximum of 1GB of ram would be used for the web server, but you'll need to tweak it to make it work nicely with loads of users. You have 250GB of space, let's say you need 50GB for yourself, you have 200GB left to sell. You could host 20-40 users on it, but limit their BW. Don't host more then 40 users, because it will kill the server.
I was thinking the same but i ask for opinion from somebody with expirience.

Thank you