I can only second Mick's post. You might find it difficult to find even a used Guild within your economic limits.

The twelve string is a curious beast and to my way of thinking there is more difference in the sounds of 12 strings than there is between 6 strings. I would encourage you to begin to make the rounds of as many used instrument stores as you can. Play as many 12's as you can stand.

Because there is considerably more tension on the guitar, 12 string's have to have sturdier construction. They tend to be more expensive than a similar 6-string. I think you will need go above $500 to get one that "works". So, make the rounds of those used instrument stores. Keep on playing the instuments and saving your money. Do not accept a guitar that is just OK in sound or in playability. If you accept a lower standard you will wind up not playing it at all.

I love my Guild 12-string, 1967 vintage. It cost me $1000 back about 10 years ago.

Roger in Baltimore