Currently, paid access games are limited. There isn't support for demos, and we can't give our friends or testers free access to a paid access game.
Sure, there are at least two ways of making a demo place (separate place or universe) but they come with flaws (an active place for no reason, players can rate the game even though they didn't buy it.)
Then we have the access. We could pay for other people's copy, but not all developers have access to this sort of thing. Remember, you either have to have money in your group or you have to pay against the tax to give your testers or friends enough to play. (Some of your people are probably NBC, meaning you have to pay a crap load to fight that 90% tax rate.)
Another issue, players can't buy access for other players. In real life, (and in steam) you could easily gift a copy of a game to another player, but not on roblox.
And the last issue, I don't know if a player bought my game or not. I'd like to know if a player bought my game during alpha/beta phases (different prices) in order to reward them. Sure, we could give a badge, but we can only do that if they join the game when they bought it. There are flaws, like if the player didn't join when he bought it, he might not get the badge as I might release the game within the next few days. Also, if a player buys access, but at the moment he buys access I update the game to where the badge are not acquirable anymore, it's too late for him.
It would be nice if these features could be implemented. (still my fav emoji)