I am the developer of a BuddyPress with 5000 members, you can see in www.autonautas.com.
I was using a shared hosting in BlueHost, but I migrated to a VPS, because of some performance issues. BussyPress is different than WordPress, specially because cache plugins aren't useful.
For instance, in my case, I need to do some fine-tuning, like configuration in MySQL settings. This configuration are not enabled in a shared hosting, but yes in a VPS. Of course you can begin with a cheaper plan an then migrate. I did that, not in Godaddy, in blue host.
If you need more help, contact me or ask here. I was working a lot with BuddyPress problems!