from what i have seen of sprint and massuh yoshi son so far i think it would be better if tmobile bought sprint out. why hasnt sprint quoted a price for TMUS if they really want to buy it? the answer is because they dont intend to give you anything more than dirt for the stock. they cant. softbank is a big hype. its got a 2/1 debt to equity ratio now. the 35 ATT offered probably the best offer TMUS will get for a long time.
If Softbank acquires TMUS, it'll be by buying out DT's stake. Regular shareholders won't see a dime, unless DT insists that's part of the deal. So even if they could afford to make the offer, AND get it approved by the US gov't, the only boost in stock price would be from positive reactions to the merger- and that's assuming the reactions would be positive.