As you probably already know, there are three "Item Collectors" in Freezeland; I call them, "the Mojyamon Trio" (although once you recruit one of them to the City, they would no longer be a trio, but anyways).
Each of these Mojyamon trades 3 Items. Some of these trades are really good, specially when you realize you can make a BIG profit from it - in fact, you can become filthy rich if you know what to trade!
We'll get to that in a moment, but first of all, these are the three Mojyamon and the Items they want and what they trade in return:
Mojyamon #1 (southeastern)
> Digimushroom for Med. Recovery
> Supercarrot for Omnipotent
> Happymushroom for Hair Grower
Mojyamon #2 (southern)
> Giant Meat for Auto Pilot
> Black Trout for Restore
> Hispeed Disk for Medicine
Mojyamon #3 (southwestern)
> Omnipotent for Sup. Off Disk
> Med. Recovery for Sup. Def Disk
> Digianchovy for Sup. Speed Disk
Alright, the deal is the following: if you trade 1 Med. Recovery (500 Bits) for 1 Sup. Def Disk (2000) you can make 1500 Bits in profit when you sell it. Now, the thing is that there's no trading limit, you can trade as much and as often as you like! Do you realize what this means? You can trade 99 Med. Recoveries for 99 Sup. Def. Disks and make 198,000 Bits in return!
Of course, if you're purchasing 99 Med. Recoveries (49,500 Bits) to trade for 99 Sup. Def Disks, then your total profit would actually be 152,100 Bits (discounting the initial investment of 49,500 from the resulting sale of 198,000). Regardless, it's a HUGE amount of Bits!
But this isn't necessarily the only way to make so many Bits, it's just the easiest way. If you notice, the southeastern Mojyamon (#1) trades you Med. Recoveries for Digimushrooms; and Med. Recovery is just the Item you need to trade for Sup. Def Disk from Mojya #3! Considering that Digimushroom is the most common Item found in the wild, collecting them throughout your journeys is a pretty easy thing to do (in fact, it requires almost no effort of your part other than picking them up as you pass them by). This way, you can also make a lot of Bits from Digimushrooms alone. Trade 1 Digimushroom for 1 Med. Recovery and then trade the Med. Recovery for 1 Sup. Def Disk and you have made 2000 Bits out of thin air!
And still there's one more way! You can also trade Digianchovies for Sup. Speed Disks too! Of course it will take more effort to do this, as you'd have to fish the Digianchovies first, but it is still a very inexpensive way of making Bits (considering all you need is Meat to get Digianchovy).
Anyways, that's how to make easy money!
NOTE: Remember that one of these Mojyamon will join the City once you've traded all Items with them (at least one of each). And it doesn't take long to realize that the middle-southern (#2) Mojyamon is the one you want to recruit (as he is the least valuable/profitable of the three). So be sure to trade the *LAST* item with him.
WARNING! Don't forget to always bring an Auto Pilot along, because whenever you trade too much you'll always get "stuck" to the Mojyamon (particularly #3, the southwestern one). This is likely due to a glitch (or who knows, maybe they did it on purpose!), but you'll be fine as long as you always carry an Auto Pilot with you.
