Would you get a topcase for this?

[masukomi]

We've fit everything into our panniers (too much of course) and are set to take off in a couple weeks, but there's one thing we keep pondering and some outside opinions would be appreciated.

Our thought is that a big empty topcase would be useful for two things:
1) food. We plan on camping as much as possible, so there will be a fair number of breakfasts and dinners we'll be cooking ourselves. Being able to throw the food into the topcase instead of trying to figure out how to keep a bag secured across the seat seems really useful.

2) jackets at border crossings, restaurants, etc. As we're heading across the Americas we figure there are going to be a lot of rather warm border crossings where it'd be nice to be able to throw your jacket into a lockable box for however many hours it takes to finish the process. Similarly, when stopping for lunch it'd be nice to be able to throw them in a case. (Yes, we've measured with a cardboard box, they'd fit.)

The last one is the the kicker though, I've got the BMW Rallye Pro 2 jacket, which has a 19" tall piece of back armor. In order to get a topcase that'd hold two jackets (with one of them being that tall) we have to shell out roughly $500 US for it and the mounting stuff. Plus the thing would have to be freaking huge ( 14" deep x 22" wide x 12" high The box from Happy-Trails ) We could probably save a bit and get a smaller one if I was willing to chop my armor, but i'm not into compromising when it comes to safety equipment.

So, while we can technically afford it $500 is a lot of money for one metal box. Do you think it's worth it for that use? Or do you think that the jacket idea isn't really that useful. We've got one of those collapsable insulated bags that we could throw a meal's worth of food in and somehow attach to the seat... We've been trying to avoid getting a topbox (seems excessive, and expensive) but the food idea really seems useful. Add in the jacket idea and I'm really close to pulling the trigger.

Thoughts?

p.s. With the exception of one quart of oil we haven't figured a place for, we've promised ourselves this would remain empty for throwing things in.