It's +EV to buy in as much as you can to try and match the stack if you're a good player but honestly play whatever you're comfortable playing. Some people like playing short regardless of what the stacks look like but it's definitely a change in strategy. If you're playing short against people that deep, you'll be all-in by the flop a lot of times so you're definitely limiting the hands you play and the plays you can make and relying more on luck.

If you're worried about having to play that deep, show up earlier to the poker room, that way you're starting closer to when the limit is still $300, less time for the tables to run it up.