Japanese Maple for $61 at COSTCO..... good deal?

[Japonicus]

so I will probably either keep it in the current tree or take it into a larger pot.

Since growing out in the ground is not an option, if you cannot fabricate a grow box for it (very simple wood box)...

...Lowes sells these nice wooden boxes that are more shallow than wide. Stained and has metal banding.
As someone else mentioned your maples buds are moving, and this seems to be the best time to begin
your transition to a more aggregate free draining type of soil. Now is the time to begin learning what the roots
are like and developing the nebari. Consider if the trunk will need to lean any or not and cut the root ball accordingly
when you remove the lower portion of roots. Had I done this with the tree above, it would have fit into this box
with a much better nebari and feeder roots closer to the trunk. I am not a fan of simply upsizing the pot. Rather
to give more room laterally for development.

 

[snowman04]

We have over 30 large landscape JM we have purchased from Costco over the last several years. A healthy 7 gallon Japanese maple for $62 is a great deal - particularly if they are uncommon cultivars or something other than the standard "bloodgood".

They are not going to be pre-bonsai - you will have to use them for air-layer stock or cuttings - but for something you can put in the ground and use as parent stock they are worth picking up.

That is what I am thinking as well. Put it in the ground and see where it goes...

 

[Paradox]

Serious question (and I will do my homework in the day/weeks/ months/years to come), would you wait a cycle to start working on the tree (chop/airlayer) or start working on it tree "now"?

I agree with @leatherback that you should formulate a plan or future vision for the tree before doing anything drastic to it.
I understand you are new to bonsai so that might be harder said than done for you at this point. Seeing the tree in the tree is one of the hardest things to learn to become good at in bonsai. So waiting a year to study the tree as others have suggested is a good plan.

However, since it is early spring and its the correct time to do so, I think it would be fine with getting it into a better training pot and soil to start it on its journey.
A good training pot would be a shorter (~5 inches deep depending on the root mass), wider (12-14 inches) pot that allows for encouraging horizontal root growth rather than deep root growth.

Then see how it grows over the next year and do some studying of your own to look at the tree and look at pictures of other trees to see what you like and what would fit with what you already have in terms of trunk shape. This will give you time to learn more about bonsai and maples in general.

 

[The Warm Canuck]

I have several of the big box store grafted JM's. I'm planning on trunk chopping soon. The root stock is usually regular ol palmatum.

Home Depot usually has them here for $35 each spring.

 

[leatherback]

I'm planning on trunk chopping soon.

chop to rootstock? (And if so, have you considered layering the variety off?)

 

[The Warm Canuck]

chop to rootstock? (And if so, have you considered layering the variety off?)

Yes, I have. One was a Dissectum, I tried layering it, I only got a few roots, (which I hear is actually pretty good for this variety). I could have left it for another year, but read how bad they do on their own roots, so I just abandoned the project. The other is a blood good, not much on top worth it. I have a few more that are interrsting varieties that I will be air layering after they get a bit bigger.