Choosing whether to buy 2.8E

For the longest time I've wanted a 2.8f, and have been saving up for one for quite a while. Just yesterday, I was quite close to closing a deal for a 2.8F (planar), but that has since fell through.

However, while browsing classifieds I found a 2.8E (planar) in pretty good condition that has been film tested for around 890USD. I have no plans to change to a prism finder, but may put in a bright screen. Do you think it's worth it to buy the 2.8E as opposed to waiting for another 2.8F to pop up at around the same price?