Just a question, are .io's cheaper than .com domains?
No, they're a good bit more expensive. Around $10 vs around $35.
The main attraction is .io is shorter than .com, and .io is newer (maybe not in a practical sense, actually newer, but in terms of mindshare) -- so some domains that might have been taken/camped for decades on .com might be open on .io. Perhaps the higher fees also leads to a little less camping.
If you help us finding a fitting name with a free .com domain I will hug you in person!!