Without trying to hijack the thread, when I registered my single letter domain names, they were all at "normal" price with "normal" renewal price.
At $400 for the "b.bike" domain in question, I will be able to have register any one of my single letter domain names for over 10 years.
1 year for b.bike or 10+ years for any one of the single domain names I have.
With that said, if you are not impatient, you can pick up a single letter domain name at a good price but you just have to be picky on what you get.
Remember, single letter domains are only good because they are considered "rare-ish".
Even with the influx of new TLDs, a single letter domain name is still "rare-ish" because most of the single letter names come with (what we have here) a premium price and maybe a premium renewal.
This tells me that they will not be purchased any time soon and thus by default remain "rare-ish".
But still to
landexiang, you have to be picky on not just the names... but also the price(s) that you pay.
At the minimum you have to break even and at $400 you will be lucky to do that considering the next person will not only have to pay the $400 to buy the domain but also $400 to renew it.
Cheers