140 is a nice aircraft. Has the Cessna wing design that are famous for their stall resistance. Some of the more exotic planes are nice but they will not forgive any mistakes and often before you get them home the gear hits the fusalage and takes the bottom out on the runway. As much as I like the 140, it should be hangered and that can add to the cost. You can get one for a good price but the annuals can cost more than the plane. There are some nice aircraft from time to time in the 40k range if you want to VFR around the airfield every other weekend but as was said, these old planes dont forgive carelessness or abuse. If you don't like the 152 then why a 140. They are similar in character. It sounds to me like you want to fly maximum range and do some overnights or camping. Old planes need careful attention and if you're not a mechanic or engineer, you might find old stuff kills you. Some might say, so bugger it, the flight is worth every minute. Is that how you feel about the 140? If not, you might consider the advantage of joining a good club. They have well maintained aircraft, often a few twins and that sort, the costs are very low in comparison to ownership and you dont have the hanger costs, insurance and annuals to worry about. If the plane gets grounded, you just step into another club aircraft. However, ownership is what it is.
RASTER