I own a good number of LLLL.com's myself.... depend on the letters and how pronounceable they are, prices vary tremendously.....
Today I sold one for $550 and 1 for $75..... If it's genuinely pronouncable meaning that it doesn't conflict with other letters in terms of how it's sounded out and how it may be spelled, I generally sell mid xx- low xxx resell. But I've sold 3 lately like that in the past two months for mid xxx end user.... so it all depends.....
But on average, pronouncable or not $35-$70 has been the range I've been noticing around the forums. (This is obviously excluding the premiums that spell out a word)