Last night, Donald Trump said he had expected to have spent $48 million by this time in the campaign. It appears he has spent less than $8 Million, so he has, so to speak, $40 million cash on hand. :-)
He had about 320M in the bank before he started the campaign.
He has a lot more than that. He unloaded his entire stock portfolio in January of 2015 for around $500 Million in anticipation of running for President.
He said he had budgeted about $35 to $40 Million for the six months before the Iowa Caucus. Which he has not spent.
So he has a lot cash on hand and he has been very judicious about spending it. He has literally run a major Presidential campaign on a shoe string.