I don't have any but I have seen a few. they look just like a mix between a jelly and a queen except the spacing between the fronds are a little wider apart.
Alsop I don't knowwhat you consider expensive but if you look on ebay under "mule palm" they'll be a listing for seedlings for $30 and even though there seedlings both jelly and queen palms are two of the fastest growing hardy palms that I know of.

The listing on ebay showed what it said was A six year old tree and I was about 15 feet tall that's tall for any palm tree expecially hardy.

The ones on ebay are listed as "double liners" which are two palms in one container, I'm not sure I would care for that. I bought my two liners from the same seller though, and mine were $15 each (total was $42 including shipping). In my opinion Pindos' grow kinda slow and Queens' grow fast, so I'm guessing the Mule should be between those two. They're listed as being hardy down to 14F.

That looks like most of the pictures Ive seen.I consider 30 dollars for seedlings very exspensive.I have seven pindo palms witch is a jelly palm.Thats just common names for Butia Capitata,and believe me there not fast growing.I bought one 10yrs ago as a 15 gallon and 10 yrs later the trunk is probley 3to4 foot tall.The hole plant is about 7ft,to me this is slow growing.I paid 8 dollars a piece for my 3 gallon pindos,and HD had them for 12 dollars for a 3 gallon last summer.I have looked on ebay and I found what I consider a good deal.I paid 99cents for a Phoenix Sylvestris,the shipping cost me 7.95.I dont know what they sell palms for in diffrent states but you can get most palms here cheap,or at least at a deasent price.Ive seen on ebay where this woman wanted 55 dollars for a 3 gallon Pindo palm,thats to me is way to much.Dont get me wrong but I know people who buy stuff and turn around and sell it on ebay for twice or three times what they paid for it.I know a person ,I wont tell there name,but they make there living off selling things on ebay for a profit.I look at ebay daily and every once and while I see pretty good deals.Its a business where most things are sold through a third person,everybody makes money off what there selling.I do see some things that come straight from the grower at good prices.Ebay is ok for some things in my opinion but not everything.

I didn't buy mine through ebay, I emailed the grower directly from his website (Mulepalm.com).

Thanks ATH,I think you was the frist person to tell me about these palms.I also emailed Mulepalm.com,and Im getting two liners like you have.They told me there more of a zone 8 palm,but there selling me three for the price of two.The guy I talked to said If I let them know how there doing in my zone,they would make me a special offer,three for the price of two.I told them I would be glad to.Thanks again for letting me know about these palms and where to get them :)

Even though they're small they really are healthy. He sends them in the little square pots so you don't have to worry about transplant shock.

I got some pictures of these nice mule palms in Jacksonville. The people in the store didn't know anything about them. Not a palm I've seen in a commercial planting before because of how pricey they are.

Wow, what a beautiful plant! Looks a little bit more like a queen palm than a butia, but that trunk is without a doubt a characteristic of the butia. Its going to look really nice when it starts getting a clear trunk.

Thanks for the pictures,I ordered two of them,one double and one single.Do you know how long they have been there?Whats the coldest temps. they have seen?They look very happy and healthy,Great Pics.thanks again for the pictures.

Definitely see some Butia blood in the leaves,nice pics!

I'm also curious as to where those Mules are located. The low for the Argyle/Jax area was 19 degrees last winter.

every mule palm loks different. some a lot more like a pindo some a lot more like a queen it just depends since theese were man made hybrid... some are just right inbetween some are a little more cold tollerant than others also. i remember someone in florida in the summer posted a pic of theirs they had since it was little and it was probally a little bigger than thoes in the pics above. they are a beautiful palm. i am going to try to get some larger ones this spring! they will obvious. stay outside all year long here which is a plus...

Considering buying a large Mule Palm to replace my Queen palm which died after our 2 consecutive harsh winters in Houston. We are typically a zone 9 but last 2 winters have gone in the 8B range. Wondering if any of you have Mules and what kind of luck you had with them during the winter. They are expensive and I want to make sure they are as truly as cold hardy as advertised before I invest in one.

In my experience Mules are at least a zone hardier than Queens. I have both and also experienced some 8b temps the winter before last and borderline this past winter. My mules retain their green foliage longer and are more robust which may speed recovery. As for their sizes, only 1 of my Queens is trunking all the rest are smaller palms.