Should I upgrade to the Nexus 4?

So I still have my iPhone 4 that I planned on sticking with until an LTE Nexus or the X-phone comes out later this year, but I'm really struggling with android lust.

I'm considering selling the iPhone 4 on ebay or maybe using gazelle (does anyone have any experience with them?) and then reselling the 8 Gb Nexus 4 after the X-phone or next Nexus comes out.

Do you think the Nexus 4 will still sell for ~$200 when the next one comes out?

Advice?