I've seen the EJ257 and the EJ207 blocks together and there isn't much difference. The nature of the 2.5 motor isn't real good for running high RPM or real high boost applications. It has an enormous amount of low end and mid range power though, as we've already seen from some tuners doing minimal tuning. All depends on what you are after.
Yes it's $1200-1400 for a complete short block. Good luck finding an EJ207 block for that price. It's generally almost twice as much. As for the EJ22T you can get the block for about the same price but most people I know who have them replace the pistons and rods and increase the CR anyways.