Horizons Unlimited - The HUBB - Help needed for paper work in Chile [Buying bike, RUB,...]

Hi,
I know that the information does exist on the hubb, but I just cannot find it.
I did lots of searches in order to find the different options one has to buy a bike in Chile with tourist visa, but even if I found some stuff, most of the time, there is not much detail much than "search the hubb".

Well, I searched, I might suck at it, but I need your help to figure out what are the positive and negative aspects of each options:

So far, what I identify is the following:

Option1: Buying a Chilean bike and register it with RUB
ð I’ve read it can be quite long before getting all the paper work done (about 3 weeks) meaning you cannot get out of Chile during that time.
ð Is it any option to make that process quicker and be able to get out of Chile maybe after a week?
ð Is it easier / quicker buying a bike new to a shop or no big difference with a used bike bought to previous owner?

Option 2 (I read something similar for Argentina, not sure for Chile): Buying a Chilean bike and get the bill of sale “signed” (or something like that) by a notary having the paper validated this way should be enough to prove the bike is not stolen and therefore enable you to cross borders
ð Anybody did this? Does it work? Is it enough not having the proper bike’s documentation at your name?
ð How much does it cost? How quick can it be done?
ð Can you get insurance if the bike is not registered under your name?
ð I guess it could be a good option to be able to cross border before the paper work is completed… if it works

Option 3: Buying a traveler’s bike
The process is not very legal as it is forbidden to sell a bike on temporal importation permit. The work around is to sell it in between borders.
Most of those bikes are registered in the US, so to put the papers in order, it requires to issue a new ownership in the US.
ð I am not US resident and have not so much close contact that could help me in the process of registering the bike
ð As the process in the US also implies about 3 weeks, The option would be to do the paper work before seeing and buying the bike, not so fine for me
ð It would be complicated to quickly sell the bike when leaving even with good discount for paper work issues.
For these negative aspects proper to my case, it is so far the least convenient option for me.

Regarding the possibility to quickly cross border, it is a worry for me as the first part of my trip will be Patagonia and implies several border crossing between Chile and Argentina.
A friend of mine wants to come, but he will only have 3 weeks and the impossibility to cross borders would be a No go for his participation.

I plan to start the trip on December 20th. Christmas might be an issue to get the paperwork done in time.

Thanks a lot for your help