...i always liked the look of the old monster beetle...
Another idea would be to grab a second-hand Monster beetle chassis of ebay and build one yourself over time. A lot of parts are still available thanks to the re-re Frog, re-re Sand Scorcher and Blackfoot III. You probably won't notice your budget blowing out because it will be over a period of time, and you will be having too much fun chasing parts, researching what fits, painting things, etc. I think money spent on something which is not what you really want is money wasted and your real dreams will be further away. On the other hand the Lunchbox and Pumpkin are great fun cars!!