Planning a caravan trip to Mexico

I am planning a trip to Mexico sometime this year. I am a native Spanish speaker and I can function as a guide during all throughout the trip. I am bilingual Spanish-English speaker and have lived in the USA for 5 years. The trip can last from 3 to 4 months, visiting about 5 interesting cities including some towns in the southwest and south of the country and perhaps also visiting also 1 or 2 "magic towns". We can create a group of 4 or 5 families or single travelers and perhaps use 3 or 4 cars. perhaps (Your sentence was getting to be too long so I split it up into two)

In The estimated value you see $1, this cost of the trip is something to that can be determined figure out later, depending on upon the type of trip different details that the group decides to do.can agree. The main goal idea is that we to share expenses equally but although the most important thing is to be able to share the experiences from the trip.

Please let me know if you are interested to in experiencing an adventure like this, so we can planned it in advance in which would be the best way.

Well done!  My corrections and changes only express my personal preferences on how your post should be worded.  There is always more than one way to say the same thing!  Keep practising your English writing skills!