I Need a New Bag

The backpack I have now, yeah, I bought it for 30$ practically on the way to Japan. I had been thinking about getting a 'real' backpack, but in the end the low price tag convinced me. And the backpacks been good in that it has a lot of space in it, and as long as I pack it lightly (in Japan no problem, I put all the heavy things in the roller) it's pretty fine. But I never intended it to become a permanent part of my travel gear - it sticks straight out, is terrible for my back and shoulders when heavy (Scotland and Belgium are great examples of suffering), and it's unwieldy on public transportation. The best I can say for it is that it makes a handy seat, and its exactly the right size to be a carry-on for Ryan-air etc.

But I'm thinking about the upcoming Eastern Europe trip, and about a possible change. Here are the options:

1.) Do Nothing

I've struggled through vacations with this backpack before, what's another one? And In will have her roller, meaning that we'll be working our days around leaving stuff in the hostel anyway.

Pros: Don't have to find or pay for a new bag right now
Cons: I'll have to pack really light, and pray that the backpack has another trip in it (it's developing a few little holes, but it'll be okay... I think

2.) Get a Cheap Roller

I've seen some cheap rollers for as little as 20 euros that should serve.

Pros: I'd match In, which is always good, my shoulders would feel free and happy, and I could bring a lot more stuff, maybe even eliminating the need to do laundry at some point.
Cons: I have a roller back home, so this would basically be a one-use thing.

3.) Get the real Backpack, at last

Pros: I'd look cool, I'm going to get one sometime in the next year anyway
Cons: I can probably get one cheaper in the U.S., I'm not sure I have the time to do it right, if In has her roller there's not that much of a point to me being extra-mobile.