He can afford, for sure.
He just doesn't want to invest his personal money in the PE. If he could save on the deposit, he would have done so. He enters a contest, and he complains that he lacks the resources of PAP. Why the fuck did he enter the contest in the first place ? Just for moments of personal glory, such as :
1. introducing his fiancée and telling Singaporeans that at 75 he still has enough sex appeal to attract someone younger than her daughter ?
2. that LKY called him and asked him to be his sifu on meditation ?
3. to tell his late mom that he has made it in life by standing for presidency, even knowing fully well that standing does not mean winning ?
I guess his objectives standing for PE have all been met, and he will not spend anything more knowing that even if he was to spend his entire fortune he would not win. He was the Chief Investment Officer of the country after all. If you spend $40,000 on ST ads, you get a half page for one day only. If he gets his deposit back from ELD, he wins big ! He has gotten one full month of publicity.