Compare the engines. The 240 will have a 4-cylinder 8-valve non-turbo engine. The 740 may have the same, it may have a turbo, and it may have a 16-valve engine. Of these 3 types, the latter 2 have more power. The turbo can need replacement at significant $$$. The 16-valve is less forgiving in that if the timing belt quits, the engine may need replacement. On the 8-valve types, a failed timing belt may leave you stranded, but the engine won't be damaged.

I would get the simpler car, the 240. Old cars have things happen and wear out that hardly any maintenance schedule can forsee. Lesser mileage and more simplicity can be the biggest difference for you.

Good Luck,

Bob

:>)