This is the toughest part of short domain investing - what about obscure TLDs that allow one and two character domains?
Minus out the mixes, beyond A1 and perhaps a couple others. Whatever value there is is in the L, LL, N, NN. The one letter and number, of course are extremely rare - very very few registrys allow them and there are only 36 possible domains when they do.
Seems like a one letter sold for $10,000 a few months ago. I doubt buyers are lacking for those. There are stories that the .LA registry has refused to renew their one character domains. I am not certain that this is happening - there have been no "OMFG what they are doing to me" threads here at NP - but if it is true then the .LA registry has set themselves back considerably in building public trust. But it should serve as a warning- all domains include the "flakey registry" risk, but obscure tlds are a lot more vunerable.
I own several LL.tlds, I consider them my most risky domains. They are not now gaining value as quickly as I would wish, there are few buyers and little traffic, although all would be considered premium domains. There is little awareness of the category - many registrars use software that does not recognise they exist, and even some versions of CPanel have to be modified before you can host LL domains.
Yet these domains really smell valuable, if you know what I mean. They are so rare, and the junkyest two letter .com is worth six figures. It is so cool to have one or a few, all it would take is a little publicity and they would be very valuable. But who knows if that will ever come. If you want to take a chance some are still available to register - .vc and .gs are the cheapest last time I looked. But put the bulk of your money elsewhere. This ship may or may not ever come in.
. (I own around 50+ one character names). IMO 2 letter names are a waste of money.
