^ thats the question. Also, on a music level, I've played Tuba for four years, and started bassoon recently. If I had a guess I would probably be around grade 2 3 ish I guess (I haven't taken any grade exams.)

I wouldn't say it's good for a beginner but I guess it's ok. You'll have to get a bigger one (88 keys) later on, though.

How much do you think those would cost?

to be honest I think it is a false economy.

I was once asked to play Moonlight sonata on a short keyboard...had to modify it obviously.
There was no pedal so I played it on "harp" mode .......
But the genius of the composer still shone through.

It'll do for a while - but not for long, so you might as well buy a full sized one and get on with it! Would you be able to get to a piano to practise, at school for example?

The cheapest full sized piano I've seen is for £400 but you probably want one which last longer than 10 years before falling apart. A good piano for a beginner would cost around £1000 - £2000. It will last you well until the future and you will still probably be playing it when you're an advanced player.

If that is too expensive you can get an electrical piano (not a keyboard!). They cost less and will still last you for quite some time but it's best to get the real thing if you can.

A five octave one might see you through the first year or so depending on progress if absolutely necessary.
I wouldn't bother with 4 octaves.... I think you'd run out of notes well before grade 1.

The Jazz band only uses the piano and I don't think my director would be to happy hearing that I wanted to try another instrument >.>

aww - How many do you play now? (I have 5 and counting )

Seriously though, PIano is very useful, but 4 octaves isn't really enough, but its better than nothing. I only cope with 4 octaves (And a keyboard at all for that matter!) by practising at school.

My feeling is that 4 octaves is too limiting and 5 is an absolute minimum.

I've never used one, but I've heard some people say that the weighted 88 note Casio keyboards are OK for their relatively low price.
e.g. something like this...
http://www.thomann.de/gb/casio_cdp100.htm?partner_id=82764

I don't like to teach piano when my students don't have one. The touch is not the same and you have to re learn how to play. I would say it is not even suitable to use a keyboard up to prep test even when touch sensitive dynamics are not the same and you can't get the feel of how to articulate.

False economy. Have you looked at hire purchase deals in music shops. In my area you can rent a piano for about thirty pounds a month and then at the end of a year if you want to you can buy the piano or you can use the money you've spent renting to put towards one of the shops other pianos. Then there's electric pianos which are a different matter entirely and will comfortably take you to the higher grades.

I play Tuba and bassoon and i'm playing around with a trumpet. I don't think my parents would be all to happy with me buying a piano because we have a small house and it is packed with stuff. If I need a five octave keyboard I would have to wait for christmas

You really need one with weighted keys at least to learn properly and I wouldn't say that 4 octaves is nearly enough. I imagine that a casio 88 key thingamy would serve your purpose well.

Reminds me of a personal experience. I had actually started on a 4 octave keybord. You'll throw it away after grade one(or two in some special cases).

I've still got mine at around Grade 5. I pratice most often at school!