Alan, how tall are you and do you want 2 or 4 seats?
With the Aero being discontinued in October you might see the depreciation slowing there and with Series 1's in the very low £30's you might just find someone that has to sell and £25 may just get it.
Otherwise, try the different trad versions to find what fits you. I drove a Roadster 100 today for about 100 miles. Once in it I found it reasonably comfortable enough but it was a struggle to get in and a bigger struggle to get out!
