The best way to buy one is to be patient. I'll give you an example.

Last week I had enough coins for 89 Linekar when he was up at about 760. I checked his price on Futbin and that checked in with the average. I had previously placed a few on my watch list to see what they sold at and I noticed one had gone at 738k.

I didn't but him at 760k as I felt it was too high so I waited. The next day on Saturday his price had gone up to 800k. This was understandable due to WL being active so i waited longer. The next day on Sunday when people had started selling of their teams his price went back down to 780k average. I refreshed the market a couple of times and managed to get one for 738k.

I used him for the WL and tbh he wasnt much different to the 87 one. I decided i was going to sell him and managed to sell him for 800k on Monday when there were around 5 on the market.

If you want to get the most from your coins with ICONs I'd say you have to be patient,monitor the market and price, take into consideration if there is the WL or if there have been and influx of players from packs SBC's and finally be lucky.