I haven't had much exposure to Lethal Weapon 3 so can't give a fair yes no opinion on it other then i do seen this game with some frequency for sale. I might have played it twice back when it was new but don't remember much about it.
As for as Time Machine goes i like the cheesy music it fits the theme well and yes the rules are not super complex. But game can be a bare sometimes hitting the ramps in the time frame given. The art and light show really do help sell this game. But has other have stated not many of these around so parts can be tough to find mainly the starwarp ramp no new ones being made yet or plastics so if the one you see for sale is working and complete i would jump on it. You will not have a hard time selling it.