Buyee is one of the more expensive ones. I wouldn't use them....They all have their own fee system.
I've actually avoided bidding using Rinkya for the same reason as their commission tables are higher and they have a flat base fee as well. The thing that sucks about Buyee is the consolidation fee they charge if you want to ship more than one auction item together. Otherwise I haven't found that they are any more expensive than the others, and they're very reliable and straightforward. For the record, these are the guys who refunded a $1.5k purchase at their expense because Japan Post was taking months to send me a refund for a lost package.
What I have found is that some services end up being cheaper for auctions below a certain price threshold, and as mentioned it matters how many auctions you're after at a time. I agree that they're all legitimate though, so the best bet is just to go look at the fee tables and determine which is best for the particular auction you're looking at
I recently used the Japonica Market service and the commission was lower than Buyee (who I generally use), but they required a deposit beforehand for the bid and did everything through email so the turn-around was slower than the other sites. They would also only ship EMS and wouldn't do SAL. Win some, lose some.
The main take-away from this though should be that using these services is not difficult or complicated. They're intentionally user friendly and internationalized web services. If someone tries telling you otherwise they're lying to you and probably have ulterior motives.
Edited by bachamn, 14 May 2015 - 01:30 PM.