Champ Colossus or wait?

cooperbigdaddy

So I have Colossus with 13 covers and a 14th cover about to expire in 3 days. It would take 119,063 ISO to champ him and then I will only have about 6,000 ISO left.

Here are my other choices:
Gamora's 14th cover comes 10/7, would take 122,485 to champ her
Doctor Doom's 14th cover comes 10/12, would take 112,944 to champ him
Kamala Khan's 14th cover comes 11/3, would take 94,783 to champ her

Or my current 12 covers:
Spider-Man will get his 13th cover on 10/3 and 14th on 11/12, currently lvl 76
Daken will get his 13th cover on 10/10 and 14th on 11/19, currently lvl 102
Cyclops will get his 13th cover on 10/26 and 14th on 12/5, currently lvl 91

Should I go ahead and champ Colossus or just sell the cover for 500 ISO (ugh! so little!) and hold on to the ISO for a better character? And if so, which character am I looking to champ?