have been thinking of getting a trex 450 or a heli of simillar size and build but I would like some input from others as to which is a good electric heli to buy and for what reasons.

Thanks

What is your experience level?
Where do you intend to fly?
What does your LHS stock on the shelf?
What is your budget like?

The answer to your question will depend on your answers to these questions.

Certainly the TRex SE is the top of the line as far as 450-class electric helicopters is concerned.
If you've never ever driven a car, would you want to learn how on a Ferrari?
Well, maybe you would, but would you be very successful?

I am a beginner but can hold a very stable hover and would need to when learning in a backyard, my intention is to have an electric model to fly after normal school days that dosen't take all the preping and cleaning. I have a venture 30 which is outstanding to fly but I wanted something smaller and quicker to get flying but also had a strong frame like the trex size heli.
flying will be local and probably private as is too far to go to model plane club all the time and the local hobby store is a member that can order mostly everything.
Budget allows about $400-500

Sounds like the TRex would be good for you, but it's costly. I just priced a basic setup : Trex "S" version, available either with metal frame or some kind of FRP, not CF but maybe G-10 i think, incl. motor, esc, gyro, battery, servos, receiver (no tx), about 750 Canadian, subtract about 15 percent for US money so that's over 6 hundred., no bling and basic servos and gyro.
You might be able to get a used one cheaper.
Whatever you get now you will eventually probably get a TRex, so you may be able to skip some steps if you can come up with a grand or so.

well I have been looking at one on ebay that has everything but rx plus spares, robably end up being about $600 enyway. I sortof want something good and expandable since I have learn't that every other time, buy something that is good and will suffice but always needs upgrading. on top of this though I still need to get a charger for the LiPo batteries, thinking the 'Swallow'. good choice?

I don't know enough to be able to recommend a charger , but there is a thread on that stuff on rcuniverse, I'm sure someone there can help you find a good one.

posted 2 of the same type of questions on different sites but havent had much success