Ebisu Rod: fishing it, gambling with a mercenary, or buying it?

Hello, I've been fishing a while and I'm nearing the level of getting an Ebisu Rod. The problem is I don't like buying a lot of of fish or fishing for them. I was wondering if it would be a good gamble to have someone who already owns one to fish them up for a trade.

From my understanding the key items for this rod can drop on the 1st trade or 500 trades. If an item was offered worth about 8 million would this be a good gamble for the merc to fish would would it be simpler to just burn buy fish? The item would be the getting of the Lu rod after getting the key items. Extra fish would be returned once a key item is found.

As a gamble if it took <100 of both types at 40k a fish each it would be less then 8 million. If it took more then 100 fish then it would exceed 8 million. Would this be a good or bad gamble for the person fishing?