I said this to someone yesterday, but I feel it bears repeating.
There is a reason why young adults move out of their parents house and pay rent for an apartment or a room in a house with roommates. It teaches us consequences and responsibility. If we don't have rent on time regularly, we stand the very real chance of being kicked out of our home. If we spend all or most of our money on frivolous shit, we don't have enough money to eat. If we are unwise with money, we end up with the power turned off or facing repossession of the car or no groceries or having to turn off Netflix or the cell phone or cable or internet to make ends meet for necessities. We learn sacrifice, we learn wants vs needs, we learn to do without, we learn to delay gratification, we learn there are real consequences for not being responsible.
What does he learn when he spends irresponsibly or blows his money on stupid shit or prioritizes wants over needs while living with Mommy and Daddy? That he'll have to pay it later when it's more convenient for him? That he'll have to eat what Mommy and Daddy make instead of indulging his Cheeto habit? That he'll have to order fewer beers at the bar? That he'll have to wait a few days to buy his new game? That his needs will always be taken care of no matter how much he indulges his wants? Paying rent isn't a waste of money, it's training how to be a responsible adult. And people who are unwilling to go through that training generally are unwilling to be uncomfortable or sacrifice for a single second to reach long term goals.
If he had saved $4000 while attending school to become qualified for his career goal, and working to save money and get through life, and giving up anything excess that he wants but doesn't need, and getting steadily closer to his goal, that would be commendable. He would have worked hard for that $4000 and given up a lot to save it for the big goals. But saving $4000 while living with his parents who cook and clean and do his laundry and pay his bills for him, while he tricks out his car and collects more toys and plays games and never progresses toward his supposed goal, while never giving up a single comfort or luxury, is bullshit.
He's never had to do laundry or cook if he didn't want to or go hungry if he fucked up or do without or deny himself or delay gratification or risk his or anyone else's needs. He's never had consequences. And he's not going to start with you if he moves from his parents house to living with you. He's learned that he will always have his needs met, always have comfort, always be bailed out, always be able to indulge his wants, and nothing bad will ever happen. If you move in together now, you will be responsible for making sure the mortgage is paid, taking care of the taxes, keeping the utilities on, saving for the future, sacrificing what you want or need while he gets anything he wants, keeping yourselves out of collections, and he will spend all his money while neither of you have any clue where it all goes. You will resent the hell out of him, while he won't understand why you're so uptight and no fun.
Unless you are prepared to be fully responsible for all finances including bills, savings, budgeting, and all of his finances, and he also is OK with this and being given an allowance with no opportunity to get more funds if he blows through it, with no resentment or bitterness from either of you, this won't work unless he sacrifices. If both of you aren't willing to deal with that (and that's not wrong, I know I couldn't), then he needs to show he can sacrifice. Whether that's "wasting" money on rent and bills and doing his own chores for him, or giving up collecting or being totally comfortable to save up a higher set goal amount of money each month to get closer to the goal of buying a house, he needs to show he can put his total comfort aside for shared goals.
If he's nearly 30 and can't see this and give up any of his wants, he never will. And you guys may be too different at a fundamental level with regard to core values to last long term. Be honest and realistic with yourself about your needs in a partner and in your life. Going into something expecting someone to change won't work. People don't change unless they absolutely have to.