Hi Archie welcome to Fodors. My sdvice would be, buy the cheapest, lightest that stays together and, if in doubt, chose the brightest colours as one day you may put it in the hold and bright colours are easier to find on the carosel.

In terms of suit maintenance, I'd try for as large a bag possible so breaking into parts just puts the weight up and/or increases chance of wrinkles.

My own bag came as part of a four bag set which cost £15 in total, bright red and all units are still working well 10 years later.

Final advice, is do not touch anything with a "brand" as generally these double the cost of a bag and make the thing vagually stealable. Choose non-branded goods at all time.

I hope this makes sense

ebags.com one of the most valuable luggage sources I have ever used and it has thousands of reviews, too.

1) Check weight of bag
2) Check weight allowance for airline
3) Go Um, that's a problem, I'd better find something lighter

Carry on? 3 days? A simple, cheap sports bag with zip sides for shoes or books. Roll garments--include a shoulder strap--bingo.