Replying to Halp.k+ for advice

Basically, i have a HDR-CX-550, and i dunno whether to sell it, how much to sell it for, basically, im stupid.

I like the quality and some of the features of the HDR like the 120 fps mode, but it has a bunch of restrictions.

I've been thinking of getting a t2i, but i dont really take many/any pictures.

If I do sell the HDR, how much could i get for it (9/10 condition)

Halp, do i stick with my cam, or move on to SLR's