Here just my 2 cents. The 2.5G Hz spectrum is not as valuable as 700Mhz. It worths 1/3 ~1/5 of 700Mhz. So my estimation of the spectrum value is around 5B (very conservative). CLWR claims its netwrok assert worths 4B. But they have to spend big money to convert it from WiMax to TD LTE. So my estimation of network assert is 2B. According CLWR's latest Quarterly balance sheet, they have 1.4B cash. So my estimation of fair value is 8.4B - 4B debt = 4.4B = $2.9 pps.
Given the fact, softbank is usually aggressive when bid, and loves TD LTE on 2.5G and already got 23B from 3 banks. The price could go north a little. However my conservative estimation of pps is around $3.