First of all, I would be skeptical of anybody who says something like “Well Akihabara is near…you don’t need anywhere else to go.” like in the link above.
Second, Japan is expensive any way you look at it. If you want cheap, look for a youth hostel and stay there. You can find plenty online, and the people you meet there might make your trip not suck as much.
Judging by your buddy icon, you might be a anime otaku or something, in which case, have fun in Akihabara.
If you really want to experience Japan though, you should make an effort to at least get to Kyoto and see kiyomizudera or SOMETHING old. And if you’re really bold, go to an onsen ryokan (温泉旅館）because the food and entire experience is fantastic (usually)

I highly recommend a hotel chain called the Toyoko Inn. Very well priced, great service, and new, clean rooms with everything you need. They are in other cities as well.

its defently cheaper to book ahead of time. but the least expensive thing would be to do a home stay with a host family, there are many really nice people that would love to acomodate you in your stay even if you only want to do that for a couple of days.

i would reccomend booking ahead of time, unless your japanese is really good, and even then, it’s nice to know you have somewhere all set up. though most capsule hotels don’t take reservations. Splitting up your hotel stays would be a great way to see more of tokyo, the yamanote line is nice and centralized, it’s one big loop, and you could stay at different locations around it. Also, i know how everyone goes on about Tokyo being so expensive, but if you’re used to living in a city in america, it’s really not that pricey. You can make it expensive if you want, but it’s also pretty easy to get around on the cheap. Don’t forget to get your JR rail pass, as that will save you a buttload of money in the long run! Youth hostels are def. a great way to go as well, we stayed at the Oak hotel in Ueno which is really a hostel, but very hotel like as well. i def. reccomend it, it’s in a great location. Have Fun!