I haven't been around a while and am not yet caught up on reading the forum. Please pardon anything that's already been addressed.
First, most of your aikido training must be with a partner. A huge part of aikido training is learning to feel your partner. Can't do that along.
Second, your cost estimate is _way_ high. You can get a good basic judo gi from Kiyota for around $40. Many, I dare say most, dojo won't require you to purchase weapons up front, if ever.
Depending on the area, you could find a dojo with tuition considerably cheaper than $70/month. It just depends on the dojo and their situation.
Our dojo, as an extreme example, is completely free. All we ask is that the members are dedicated to their training. Oddly, the free tuition doesn't turn out to be a bonus for the 99% of the people we talk to.
Go try Aikido somewhere. If your finances are very lean, talk to the Sensei. They will very probably find a way for you to offset the tuition cost.