I have a small workshop, tools, and I have been collecting
plans, and doing a lot of forum reading over the last few
months, here are the problems I ran into.
(1) Cost of parts may be more than buying used, and even
new sometimes.
(2) Availability of parts, stuff like some of the comet series
CVTs, and also in some of the plans I have call for car
parts, or even parts that would be imposable to make
from scratch with just simple tools.
-- Most plans that do call for car parts or custom made
parts, are of the mini-buggy to full blown dune buggy
type, but few regular old Gokart plans use car parts
or custom made parts.
I have still chosen to make a mini-buggy from plans,
because.
(1) it will be fun

.
(2) If I made it, it should be easy to fix, or it would
be easy to replace parts as they break or wear out.
(3) I can pay out the cost of D.I.Y mini-buggy slowly
over time as I acquire the parts for it.
(4) I will learn something.
However, the total cost of the parts for my mini-buggy
is almost the same as a factory made mini-buggy, and
if I had that money to spend, it might be tempting
