I cant see how these people can do it at the price and make a profit that would justify the capital investment so i am driven to the conclusion thay a corner is being cut some place.
I have looked at leasing out a two seat trainer (PA 38/C152/T67) and the costs of insurance ,maintenance, and depreciation run out at about £ 35 with a modest profit to add to this a VP prop ,retractable gear ,auto pilot and a better avionic fit of the PA28R and the £45 is to good to be true.
If the deal is as good as stated then go for it but i would take a LONG hard look at the small print.