hi melisa,
scooter rental in prohibited i Seychelles, how ever if you are comfortable with riding bikes in steep mountainous roads, you can buy a scooter for 40,000 to 50,000 scr.
for long term car rentals, it will be 12,500 to 13,000 scr per month for a small car.
if you haven't found your accommodation yet, a single bedroom flat in Seychelles will typically be at 6500 scr to 7000 scr average, but hard to find close to the market as you have move around to find vegetables, groceries are available at most of the places in mahe island, the accommodates are bit cheaper in central and south part of mahe compared to the north.
thanks
karthik