Yeah, you're well within the Random Teleport range, so chances are you are going to continue to be raided and griefed until you move. You may have built quite a base at this point, but you are going to expend more energy keeping it built and replenishing your supplies than if you go further out. I agree with javon's advice, 50k out would keep you fairly safe for a while and you wouldn't have to constantly worry about getting raided.
Asking whoever is doing it to simply stop isn't going to work, for a couple reasons:
- there are no repercussions for their actions since raiding and griefing is perfectly fine
- it's most likely more than one player-- being that close to spawn it's probably a bunch of different players that keep finding your base.
In the end, it's your own decision; we can only offer advice from experience :)