I have some old fest currency: Faded Valentine x4, Withered Shamrock x25, Sanctuary of Saerielle Badge x5, Decorated Silver Eggling x24
And the avatar items I have are: Sylestia's 1st Anniversary Party Hat, Lovely Glaive, Lucky Scythe, Red Myconid Staff, Bouquet of Black Roses, Bouquet of Pink Roses, Lovely Black Rose, Mossy Worn Staff, Crimson Crown of the Oracle, Leprechaun Hat

Okay so the old fest currency isn't really going to be worth much. You can try to sell them as a novelty but I don't know anyone who would want to buy it. If you have the space I see no harm in keeping it, though. Maybe some day people will want to collect them.

So, first thing you should know if that most fest items are still obtainable through Retired Chests that you can buy during their respective fests. The Anniversary Hat is so expensive because it's not obtainable through a retired chest. So even though those are all old items it doesn't mean they're rare.

1st Anniversary Party Hat: 2mil+
Lovely Glaive: <50k
Lucky Scythe: <50k
Red Myconid Staff: 5k-15k This is an explore item and is still common
Bouquet of Black Roses: 5k-15k
Bouquet of Pink Roses: 5k-15k
Lovely Black Rose: 5k-15k
Mossy Worn Staff: <5k An explore item and pretty common.
Crimson Crown of the Oracle: 25k-100k This is an explore item. It's not super common but it's not very sought after.
Leprechaun Hat: <50k

Okay, that's good to know. I was wondering if the items there was a way to get older items (or if the items were even retired xD). I didn't see them on the broker, so I wasn't sure. I appreciate the information, definitely helps. I'll probably look into selling the Party Hat and just keeping the other stuff. xD

Another question, is there a way to see pets you've released in the past? I saw that you can get them back for 50 gems, but I wasn't sure if that is just for recently released pets or pets from any time.

Items show up a lot more during their associated fest so if you want to buy them it's a lot easier to find them then.

This is the Advanced Search. It's under the Social bar at the top. You can search for pets on that with. Put in your Username and select 'Yes' under 'Released' to get a list. You can get back any released pet at any time.

Oh awesome. I really appreciate you answering all my questions. Makes things a lot easier to get back into. xD
Are people interested in low-ID pets at all?

Oh don't worry about it! I'm more than happy to help. ^__^

It's not something that is typically sought after but there are some who will look for them. You can always make an offer thread to see if there's any interest out there.

Oh, so I don't remember if they were a thing when you played but Themed pets (pets with specific color schemes decided by the admins) have tags on them now that show what theme they are. Like this one. You can see the theme in purple above their genes. Themes are worth more than regular tamed pets because they're available in limited quantity. How much they're worth depends HEAVILY on what theme. Some are much more rare than others.

The reason I mention is that themes existed before the tags were put on. So themed pets without the tags are called pre-tags. And those are worth a LOT. So if you have any pet that you caught during an event, don't go selling it before finding out if it's a pre-tag or not. There's a list around the forums somewhere of what the pre-tagged themes are... I'll have to find it...

Was this the guide? https://www.sylestia.com/forums/?thread=55275

Thank you for the information and the guide! It doesn't look like I have any pre-tags. I only have a few pets from 2013 and just my starter from 2012. Looks like I didn't place much until 2014, unfortunately.
I've been enjoying my return though. Definitely seems like a lot of cool stuff to do.

Ah, it was worth a shot. And you're quite welcome.

Feel free to contact me if you have any other questions. ^__^ Always happy to help best I can!