So I'm fairly new to the world of auctions beyond eBay, having won my first coin from a European auction last month, and currently bidding on another. One of the things I've had to get used to is trying to estimate buyer's fees, shipping, PayPal charges, etc. I know one size doesn't fit all, but I sat down and worked out a chart to help me quickly figure out, for example, what a 250 Euro bid might look like in dollars. I've estimated a 20% buyer's fee at the more liberal end. I think I've seen everything from 15 to 22, with 18 being pretty common. The chart is just an estimate, and it becomes increasingly flawed since a high dollar purchase would probably necessitate more expensive shipping and might be paid in a form other than PayPal. But I suspect my purchases will be no more than a few hundred dollars, and I thought the chart might be of interest to others. Later I might work up one for pounds for British auctions. Swiss francs seem to be trading at 1:1 with the dollar right now. The Euro is pretty close too.
I think the conversion fee is typically 3-4%. You can avoid both the PayPal fee and most of the conversion fee by using TransferWise, though.
You can use the online spreadsheet to create these, just make the conversion rate, buyer's fee, etc. as parameters. Then create rows referring back to those parameter cells every 5 or 10 like you did. Easy to update for a new auction and good as a cheat sheet until you are comfortable. After a little while, you'll instinctively understand Euros or Pounds or whatever. It's just like learning Celsius temperatures. 10 get out the sweater 15 is cool 20 is starting to get cool 25 is nice 30 is warm 35 is blasted hot
