Thing is Tim's at that point in the relationship where he can see school friends on social media having fun, enjoying life with their kids, and regularly socialising. However thanks to some poor judgements and some consistent bending over, he's found himself stuck in a bland marriage to the hot chick who's slowly lessened her care in herself to become a luke-warm mess. The kid he has isn't really interested in the things he expected them to be into (aka.. all the cool stuff he likes) and his wife constantly keeps remotely hinting at having a second child, not that it'll happen, but to give him faint hope of a larger family.
He's lost his ability to concentrate on a hobby, as the vlog which has now become their primary source of income is taking ever more time off them to produce, which in turn has also turned them into treating each other more as business partners, reliant on the income to survive. Hence why they need to keep splurging on material items and expensive stays, in the hopes that each time, this splurge will be the one that brings that missing set of happiness back into their lives.
You saw glimmers of it during the Roy O Disney suite tour, hence why their doing it again, under the belief that's the life they need to be in to be happy. Its the same smile that Tim had when he got his Lego set at Christmas, and when he got his chance to geek out on the galactic star cruiser.
See Tim's weakness is 'substance' abuse. what was originally subdued with recreational alcohol and a little smoke is now changed to hording stuff. He needs that 'desirable' material item, be it exclusive Lego, concierge level access, DVC access, etc. Something that gets him a perk level above the normal person, to justify his value to society and to justify where he fits in the social status of his peers. It's also the reason he puts up with as much crap as he does from Jenn, as if he's using the perks as a way of balancing the scales for how far she's fallen since he fell for the 'Hot chick' who was well above his league.