How much should I save before moving?

Long story short, me and my bf have been together 4 years and decided we didn't want to do long distance, we want to live together, move somewhere else honestly. My mom is moving, but she is moving far from where we originally stay. We always talked about moving in together, and that's a whole different subject. I was wondering what around should we save. Nothing online gives me a good estimate. I was thinking within the next 1.5 years  if we have $8,000+ saved that would give us a head start and he transfers(Walmart) and if i transfer from my job. He makes about $700 on every check bieeekly  and I make $400 + tips + I earn a extra $200 on the side. So about $900 on a check biweekly.