While trying to buy some vermillion I bid on one lot that had 45 minutes left. I found another for the same price but that was 1 day+ and bid on that as well, only to then notice my bid was already on it. It seems as if one lot is somehow two with separate countdowns. My bids went through on both. As well, I'm not sure if it's intended but I was able to outbid myself which isn't usually possible on these kinds of things. Not sure if this is intended to be different here but it doesn't make sense.

I don't know about the multiple lots thing, but I know that you are able to outbid yourself as I have done that before too. It's useful in cases where you're down to just seconds left of a bid that has multiple users trying to get the pet/item. There could be snipers out to outbid you at the last second so being able to outbid yourself could enlarge the gap between the prices and help to ensure you get the item.

Could you please provide the links to the lots that you suppose to be duplicated?

Outbidding yourself is intended as Sylviianel explained. A bidder always has a possibility to raise a bid if they wish to be sure that they'll win the auction.

Unfortunately the lots seem to have expired. If it happens again I'll make sure to screenshot.

Screenshots won't help unless they contain the page url. We need lot id which can be found in the lot link. Maybe you have them saved? If not, please save the links in case if you encounter the same thing again. I'm leaving this thread open for now. Thank you!

Well there's a couple trade lots for that day in my history so here you go:

http://beastkeeper.com/lot/3/223587/

http://beastkeeper.com/lot/3/223256

Don't know if that'll help because I can't remember if the URL was the same for both trades or not, I just remember there being two listings for 1 vermillion each so I clicked both, made an offer on each one in two tabs then when the page refreshed on the second one I noticed that I'd bid twice and the change was reflected on the first lot as well.

Yes, if I took screenshots next time I would make sure to take a picture of the entire screen so I could post the lot ID.

I checked both these lots. These surely two different lots, and only the second one has two your bids made with an interval of 37 seconds, the second one incrementing the first one, so probably this is not the case.

Yeah I wasn't sure if those were the right links since both are expired. I'll take a screenshot if it ever happens again.

I'm not too sure if this is a bug but I just found a lot where there are 2400 vermillion, but I'm pretty sure the cap was suppose to be 999. Here is the link.

http://beastkeeper.com/lot/3/226014/

It's not a bug. It was possible to accumulate this much before the limit was introduced. It's also possible to put any amount of the item to auction if a seller has enough of it.