I agree with you about the scaremongering hype from both sides. It's impossible to put an actual figure on any amount of money saved/lost, because we just don't know what's going to happen in the future. However, what really sways it for me is that BREXITERs don't even seem to have a plan - not one they're prepared to admit in public, anyway.
Admittedly things don't always go to plan, but if there isn't a plan in the first place, nobody knows which way to head. There have been vague mutterings about having trade agreements with non-EU countries, assurances that trade with the EU will carry on as usual, promises that the money saved will go into the NHS, but there are absolutely no guarantees that any of this will happen and it just seems like 'back of a fag packet' stuff. We cannot ever go back 50 years, so we have to think to the future and I'm not convinced that any of the BREXIT politicians actually have.
Looking at the history of the BREXIT politicians, most of them are neoliberal in the American sense (ie. small state, minimal regulation and few social safety nets), veer towards being more 'friendly' with the US and are on record as wanting to increase privatisation in the NHS. This isn't a way I want to go. The EU isn't perfect, but I prefer the European social democratic model.