Two very different DAPs. I have both. I like both. You can load 24GB (give or take) onto the 8GB Clip+ ($62 on Amazon) via 16GB micro card, but that will cost you another $45 or so. So that combo is about $110 for a very nice 24GB DAP. The Sonys are $338 for 32GB and $278 for 16GB. So the multiple is 3x not 10x.
SQ-wise, I think it depends on the phones. The CK10s I own diminish the SQ gap between the two DAPs, when I have flac files on the Clip+ and 192 and higher WMA and MP3s on the X.
EQ-wise, the Sony is a much better purchase, if you need it. I like the Clear bass in particular (the only slider I use).
As for the power to drive your phones, that I can not answer. I do have to crank both players to near max for some tracks, usually older rips with less compression in the original mastering (classic rock, for example). But with newer music, much of it mastered for loudness, that isn't the case.
Another option is to watch for Woot! sales on the Fuze, which has basically the same SQ as the Clip+. I just nabbed one for $27 (2GB) and plan on using my 16GB micro card with it.